#7x0x

This time last year, Elementary creator and showrunner Rob Doherty received a call he wasn't quite expecting: CBS was picking up a seventh season of the modern-day Holmes-Watson detective mystery. The surprise pickup, which would later be announced as the show's final season, threw everyone for a loop -- mainly because an ending was already in place.

"Even though I didn't want things to end in season six, I felt very satisfied with the finale. I know that Jonny [Lee Miller], Lucy [Liu], Aidan [Quinn] and John [Michael Hill] felt good about it," Doherty tells ET. "To be honest, I was a little hesitant to explore the possibility of a seventh season. It wasn't quite, at least initially, the cherry on top. We thought we had already placed our cherry. [But] ultimately, it was a blessing because between the writing staff, the cast, the crew and post production, it really was a family. So to have this extra time with our Elementary family was a great thing."

A lot will have changed since the events of the season six finale, which saw a deep rift form between Sherlock Holmes (Miller) and Captain Gregson (Quinn) following the death of serial killer Michael Rowan and the aftermath that followed. When things pick back up, a year has passed, and Sherlock and a newly blonde Joan Watson (Liu) -- more on that later -- are across the pond in London working alongside Scotland Yard doing what they do best: catching elusive bad guys. (Watch ET's exclusive clip above featuring Miller, Liu and Tamsin Grieg, playing Scotland Yard's DCI Athelney Jones.)

But it's not all hunky dory for the PIs, most notably Joan, who grows increasingly homesick for life in New York City. With the core foursome of Sherlock, Joan, Gregson and Bell split up at the start of this final run, just how will they come back together? Ahead of Elementary's final season, ET spoke with Doherty to get his thoughts on how he approached these last episodes, the challenge of constructing a wholly new ending, Sherlock and Joan's new foe and yes, the origins of Liu's new blonde 'do.

ET: Were you surprised at all that the show was returning for a seventh season? Rob Doherty: You know, it's funny. I was surprised and yet at the same time, if you'd asked me a few years ago, I would have presumed the show would go seven years, if that makes any sense. As we were getting into the sixth season, it just seemed less and less likely. We couldn't really get an answer one way or another. And so it started to feel like we needed to plan to end it. Our intention was to finish the series in the sixth season. We did that, and then lo and behold, there was a request for a seventh, and there was much rejoicing, as they say.

What was the creative mandate that you wanted to follow in this final season? Because the seventh season is only 13 episodes, it's more serialized. We were thinking about the finale as we broke the first episode. We were already close to the end, or at least it felt that way, so going into the season, we had a few big-picture items that we wanted to tend to. One was seeing if we could heal the very fractured relationship between Sherlock and Gregson. That was an important element for the season. There were some personal things in Joan's life that we wanted to explore a bit more. We didn't really have a chance to wrap up certain storylines for her in season six because of the way it was structured. And so, getting into season seven and looking ahead to the finale, we wanted to position Joan for some big changes in her life.

You're referring to the fact that Joan gave up the opportunity to become a mother and adopt a baby? Yeah. The big questions for Joan are: Where does she really belong? As season six wrapped up, she made a big decision to join Sherlock in London. She had, over the course of the season, explored the possibility of becoming a parent. We felt we had more stories to tell on that front. It's something that she will reexamine over the course of this year.

At the start of the season, Sherlock and Joan are in London working with Scotland Yard. It's a slightly different situation than they're used to in New York, but they are both handling their new reality differently. Can you preview that side of it for us? In a lot of ways, it's the flip side of the Elementary pilot. Joan is the fish out of water. Joan is the one who has to navigate the new landscape [and] find new friends. She's getting a taste of what it was like for Sherlock when he came to New York and carved out a role for himself there. For Sherlock, it's a homecoming. He's in the place that he is, arguably, supposed to be. There's less of an adjustment period for him.

In many respects, it's very similar to their experience in New York. They're working in Scotland Yard. They have their cases, both personal and professional, and they are as devoted to the work as they ever were, but it's just not the same. Joan has family she's very close to that she misses. Joan is as much a creature of New York as Sherlock is a creature of London. It's tricky. When we join them, we're going to start to see cracks appearing in the partnership, and there's some conversation that's due about whether moving to London was the right move or not.

It's only a matter of time before Sherlock, Joan, Gregson and Bell come together again. Under what kind of circumstances could this manifest itself? We left Sherlock and Gregson in a very bad place at the end of season six. The captain was willing to let Joan remain a suspect in the murder of Michael Rowan because he knew that the truth was his daughter actually killed Michael. Sherlock figured this out and confronted him. It was a really powerful scene to see Sherlock and Gregson really go after each other, but a seventh season represented an opportunity to heal that rift. But it's going to be very difficult, not just because there's so much bad blood between them. Suffice it to say it's going to be even more difficult than they thought to come back together as friends and colleagues.

Do you think that that's even a possibility -- that Sherlock and Gregson could somehow put this whole situation behind them? My sense always was that, whether there had been a seventh season or not, that they would come back together. I've always looked at them as a family unit and the four of them have been through too much together to stay apart forever. That's certainly the way we attacked the problem this year. They're all grown-ups, they're all very dear friends and as we'll see very quickly, in times of trouble, they put a lot of that personal stuff aside. Very quickly they'll have bigger and more important problems to get to and I think a lot of hurt feelings will fall by the wayside.

Sherlock and Joan will be facing a new foe, Odin Reichenbach, played by James Frain. Can you set up their new target? We wanted a threat to Sherlock and Joan that was even more present. There is a larger, more serialized case that they will tackle as of the end of the first episode and it won't be long before they find themselves in the orbit of a tech mogul by the name of Odin Reichenbach. And at least initially, he seems like a potentially good friend for two detectives to have. He has access to data around the globe. But the closer they get to him, they realize that he's as dangerous as he is powerful.

I must ask you about Lucy's blonde hair because it is quite a dramatic new look for Joan, and the hair color change is even referenced in the first episode. Was that a creative conversation you had with Lucy or something she wanted to do? I have a very detailed recollection of this. I was at my son's Little League baseball game when I got the call from the network that we were officially coming back for a seventh season and I immediately texted Jonny and Lucy. Lucy wrote back, "I'm a blonde now" or "I have blonde hair now," and I texted back, "Haha very funny." And then she texted, "No, I'm serious." At that point, I very quickly wrote back, "Can't wait to see it, bet it looks amazing!" That was the discussion. The show had ended, Lucy was looking for a change. She didn't really have to worry about whether Joan Watson would do it or not, and it was great! Lucy looked beautiful no matter what she did with her hair, so it was nothing that any of us worried about even a little.

Because you thought the show was done after season six, did you save anything in your back pocket on the off-chance you'd get a bonus season?We left it all off the field [in season six]. There wasn't much that we missed when it was all said and done. We felt we had done what we wanted to do in the final season. When we had this opportunity to do one more year, we just started from scratch again. We knew we had to reset the table, as it were, and bring our core group back together. But beyond that, we weren't sitting on a finale, we just wanted to re-situate everyone as best we could and then look for something that felt appropriate. Ultimately, we looked back to canon to see how Arthur Conan Doyle might have spun it, and found great inspiration there. People who are familiar with the original stories will recognize some of our moves as we get towards the end of the season.

How do you feel about the way the story ends, since you knew going in that this was it? I'm very proud of the way we ended things. You hate to have one good finale and one bad finale. Even though I was nervous going into it and had a few sleepless nights as we started to search for another series finale, I feel really good about where we went. I hope anyone who enjoyed the original series finale will enjoy this one just as much.

In addition to dealing with a serious case of homesickness and the baggage they left behind in New York City, the PI duo — who are now working as consultants for Scotland Yard -— will find themselves challenged by “their greatest foe to date” this season, per the network description.

Below, showrunner Rob Doherty previews the “life-altering decisions” ahead for the characters, as well as Sherlock and Joan’s new frenemy.

TVLINE | You knew going into Season 7 that it would be the final one. How did that shape the story that you were telling this year? We knew going into the season that all bets were off and we could make big moves with our core cast. We made a pretty big move in the first episode. As we approach the final handful of episodes, that’s when we looked at moves we typically wouldn’t make, life-altering decisions for the various characters, but especially Sherlock and Joan. In Joan’s case, there were things that I wanted to see her accomplish, personally, in different seasons that were too challenging to pull off at that time, but felt appropriate to a final batch of episodes.

TVLINE | The premiere picks up one year later. How has life changed for the characters in the time that has passed? [Sherlock and Joan] are working with law enforcement in the UK. They have found the British equivalent of Captain Gregson in a DCI by the name of Athelney Jones. That’s a name that will probably be familiar to people who are knowledgable when it comes to the canon. Athelney Jones was an investigator that the original Holmes and Watson worked with in the stories and books. For Sherlock, it’s a homecoming — for lots of reasons. In any iteration of Sherlock Holmes, he’s of that place. He personifies London in a way. So for him, the transition’s been relatively simply and certainly made easier by Joan’s decision to join him there. I think when he chose to accept the blame for what happened to Michael Rowan, he was ready to go it alone in London. And then Joan made a decision that allowed them to be partners again. So he’s really gotten the best of both worlds. For Joan, understandably, it’s more of a challenge. She’s certainly a worldly person, but has never really spent meaningful time outside of New York. In the same way Sherlock is of London, Joan is of New York. And so there’s more of a learning curve for her. There’s been a greater adjustment period. So as we catch up with them a year later, we’re going to take some time to see what’s the same for them as partners and flatmates, and what’s different.

TVLINE | Joan has also possibly made a bit of a sacrifice by giving up on the idea of adopting and starting a family. How is that going to impact her this season? Is that something she might change her mind about? It’s something that we will speak to in the first episode. It was exciting for us to put her on that path in the sixth season, but that season ended with a very close call with Michael Rowan. He nearly killed her in her home. We’ll talk about that in the premiere, and we’ll show that it is informing her thinking about whether or not to pursue starting a family again.

TVLINE | How are things back home with Gregson and Bell? It’s been a much more difficult time for them in that they’re both sitting on a tremendous secret, which is: The captain’s daughter killed Michael Rowan and allowed Joan to become a suspect. Captain Gregson was a party to the cover-up, and Marcus knows this. There’s been a healthy amount of stress on their relationship. For Gregson, it’s a lot harder because things ended so badly between him and Sherlock at the end of Season 6. As a staff, that’s one of the things we looked forward to tackling with this pleasant surprise of a seventh season. We loved the way Season 6 ended, and yet it hurt us to leave Sherlock and Gregson on such unfriendly terms. In this first episode, we will spend some time in New York, [and] we will see where Marcus and Gregson are in their lives. But like I said, there’s a pretty big elephant in the room for the two of them.

The captain’s “prognosis is something that will hang over Sherlock and Joan and Bell, certainly, over the first handful of episodes,” Doherty continues. “That’s something that’s going to resolve itself one way or another, and they need to keep their heads down and do the only thing they can to help him, which is try and find out who tried to kill him and why. It won’t be neat work. They’re going to have to exhaust a lot of resources to find the culprit and put themselves at great risk.” In fact, Doherty warns that the closer the PI duo come to resolving the case, “the closer they find themselves to an incredibly dangerous person.”

Needless to say, Sherlock and Joan will be making the trek from London back to New York City, but it’s not so much a homecoming as a temporary visit, in their minds. “As far as they know, they’re coming home to help with ‘a family problem,'” Doherty says. “The circumstances don’t necessarily dictate them staying in New York forever, and in fact, Sherlock is not welcome there.” Since he took the blame for Michael Rowan’s murder before departing for England, “a return for Sherlock is dangerous. If he’s detected, he could go to prison for the rest of his life. So he’ll have to consider the possibility of working with Joan remotely, or risking a life sentence in the U.S.”

Elementary wrapped up Season 6 on Monday night by moving Sherlock and Joan across the pond. So how did the duo find themselves in London? After discovering that Hannah killed Michael, and that Captain Gregson was protecting his daughter, Sherlock confessed to the murder to cover for prime suspect Joan. Rather than going to jail, the PI made a deal which allowed him to keep living and working in London… and his partner followed him to Baker Street!

Below, Doherty talks about the location twist, which was borne out of believing that the show was coming to an end — don’t worry, it’s not — and Sherlock and Joan’s feelings for each other.

TVLINE | Talk to me about the decision to kill off Michael. Did you hesitate at all to lose him as a villain? No, there was no hesitation. At the same time, I can’t say that was the plan from go. The season finale was, in fact, shot in the 13th slot of a 21-episode season. Initially, we had an order for 13 episodes. We got to a point, schedule-wise, where we couldn’t wait for an order for more, and just had to assume [Episode] 13 was the end of the season, and potentially the end of the series. We had to factor those things into our arc with Michael. So as we’re approaching what we think is truly the end, we didn’t want to focus on Michael. We wanted to focus on Sherlock and Joan, and we didn’t want their lives at stake. We wanted their livelihood and their partnership at stake. Taking Michael off the board when we did cleared a path to tell a story that, if it really was the end of the show, would feel like a proper wrap-up for everybody.

I also confess to being attracted to the idea that we’ve primed everyone for a real duel with this very peculiar villain at the end of the season. I liked clearing a runway for that, and then killing him. [Laughs] I liked the surprise of it — that, in fact, Michael is not going to be the final problem. It’s the fallout of that, it’s the fact that Michael died, and it’s bringing all sorts of unwanted attention to Sherlock and Joan, and putting everything they do in jeopardy.

TVLINE | Had you known that you were going to get more episodes, would you have used Michael more in between? Yes, absolutely. Had we known from go that it was a 21-episode season, we absolutely would have spent more time with Michael. Desmond [Harrington], who played Michael, was phenomenal, just an incredible person, and a great presence to have on the set, and he made Michael everything we wanted the character to be. We were having a good time together, and it would’ve been great to find a few more slots to keep Michael alive, so to speak. But we had to tell that story a certain way. And then it became this very unique challenge once we finally did get an additional order to tell stories that could be placed in front of the finale that we had already written and produced.

TVLINE | As you were approaching this finale, did you always have Hannah in mind as the killer, or did you go through variations of who it could be? I’d say everything in the finale was sort of born whole. It was kind of of a piece. By the time we made the decision to kill Michael in [Episode] 12, we knew that we wanted Joan to become the suspect. And once Joan is supposed to be the suspect, we looked around for who else has a motive, and Hannah certainly did, because of what Michael had done to her roommate in a previous episode. Forensically, Hannah made sense. There could be some good forensic confusion that would seem to implicate Joan. So once we knew we were killing Michael, and we wanted Joan to take the fall, Hannah was really the only and best option for us.

The other thing that we loved about Hannah as the killer is that it put Gregson in such a terrible spot. It was interesting to take someone who is never anything but an ally and friend and champion, and make him part of the problem. To put him and Sherlock up against each other, we thought, was a big and interesting thing to do in a finale.

TVLINE | You end this finale in a completely different location. How much time are you going to be spending in England next season? I don’t know if I can say much more than we will absolutely be in England as the seventh season begins. We had to commit. We chose to move Sherlock and Joan to London at the end of the season because we felt it was canonically appropriate, for lack of a better term. We really liked the idea of taking our Holmes and our Watson, and putting them where, really, a Holmes and a Watson belong — bring them home, so to speak — and let everyone imagine that there are additional adventures and mysteries ahead of them in a place where they really belong.

TVLINE | How will Sherlock and Joan’s partnership and the work that they do be changed going forward? Their work is really cut out for them, as we move into a seventh season. By the end of the season finale, we’ve established that their relationship with the FBI is in tatters. That’s never good. Their relationship with Captain Gregson is in a bad place. Sherlock is not allowed to set foot in the states without being arrested, and yet they both feel a pull to the place where they spent the better part of a decade together, and to the people they’ve worked with previously. They’ll certainly be exploring an opportunity to work in New York again, but a lot of problems exist, personally and professionally.

TVLINE | You reached a new depth with Sherlock and Joan’s relationship this year. Sherlock even says to her, “We’re two people who love each other.” How will their personal relationship evolve in the new season? You’re talking about a scene that killed me to write because it was my goodbye, too. I had to assume this was the end for the series. So I thought it was time for Sherlock to stop beating around the bushes and let the subtext be the text for once. When you look at any of our seasons, what you see or feel between them is love. I think that’s the way it is for all Watsons and Holmes, or Holmeses. I don’t know what the plural is… Yes, there’s respect and friendship, but I think a Watson loves his or her Holmes, and vice versa. It’s underneath everything we do, and yet I didn’t want the show to end without somebody making that explicit. The challenge, of course, now that there’s a seventh season, is continuing to explore that and expand upon it. I don’t think it was any great revelation to Joan that Sherlock felt that way, because she feels the same. There’s nothing embarrassing about it. I don’t think it’s anything Sherlock regretted saying. But it’s something that they’ll both compartmentalize, and put away as they continue to move forward together.