As mentioned earlier, here's my Halcyon Green theory that stems from my reread last night.
A quick disclaimer, though. All pages will be from my copies: US first edition of The Demigod Diaries from 2012; US paperback edition of The Last Olympian from 2011; US hardcover first edition of Blood of Olympus from 2014
My theory is that Apollo wasn't responsible, or at least solely responsible, for Hal's curse. I will explain my reasoning shortly, but I think it's benificial to look at how the text explains the curse.
This is how Hal explains his curse at the beginning, through the voice of the leucrotae:
"I have lost count [of how long Hal had been trapped]. Decades? Because my father is the god of oracles, I was born with the curse of seeing the future. Apollo warned me to keep quiet. He told me to never share what I saw because it would anger the gods. But many years ago... I simply had to speak. I met a young girl who was destined to die in an accident. I saved her life by telling her the future."
...
"[The gods] don't like mortals meddling with fate," ... "My father cursed me. He forced me to wear these clothes, the skin of Python, who once guarded the Oracle of Delphi, as a reminder that I was not an oracle. He took away my voice and locked ne in this mansion, my boyhood home. Then the gods sent the leucrotae to guard me. Normally, the leucrotae only mimic human speech, but these are linked to my thoughts. They speak for me. They keep me alive as bait, to lure other demigods. It was Apollo's way of reminding me, forever, that my voice would only lead others to their doom." (24–25)
So, Hal genuinely believes that Apollo is the one who cursed him, at least at the beginning. But, we see something shift in him after seeing Luke's fate. His immediate reaction to seeing Luke's fate is that "[h]e yanked his hands away and stared at [Luke] in terror" (42). Luke even notes that he, "could swear the old man was terrified of me now" (43). It's clear, based on what we know from The Last Olympian, what Hal saw was Luke's part in the war, and specifically his hosting Kronos, as evident in the way he describes what he saw: a sacrifice, a choice, and a betrayal (42).
This vision is what allows Hal to see truly what had happened. When Luke asked what scared Hal so badly, he responded, "I think I finally understand why I was cursed... Apollo was right. Sometimes the future really is best left a mystery" (48). This vision changed the vengeful Hal shown just that morning into the Hal who's last words as he burnt down his home as well as the leucrotae were the battle cry, "For Apollo! (50)"
I'll talked a little bit about how Luke misconstrued Hal's message of promise in my earlier post about Alison Simms, so I won't go into further details on that in this post, instead focusing back on my initial claim: that Apollo wasn't solely responsible for Halcyon's curse.
As shown in the excerpts, Hal does genuinely believe it is Apollo, even as he starkly learns to accept his curse as well as his fate. And I do think, at least most of the time, it was genuinely Apollo there, but I think that Apollo was forced to curse him, or that someone in the form of Apollo was the one who did the initial curse, while the true Apollo is left to pick up the scraps.
Apollo is, overarchingly, a good parent. He loves his children; he gives them gifts:
"That was my last sonic arrow," Michael [Yew] said.
"A gift from your dad?" [Percy] asked. "God of music?"
Michael grinned wickedly. (184)
and Will notes how odd it is that Apollo hasn't visited dreams in Blood of Olympus:
"We don't know what's going on at Delphi," ... "My dad hasn't answered any prayers, or appeared in any dreams... I mean, all the gods have been silent, but this isn't like Apollo. Something's wrong" (135–135).
And at multiple points throughout Trials of Apollo we see this immense love for his children, that it's far too many for me to even quote as evidence.
The only of his children, besides Hal, who is not fiercely devoted to him is Trophonius, who, as I said earlier today, was a victim of circumstance. Trophonius used his powers for thievery, and Apollo let him suffer the consequences of his actions; which lead to him cutting of Agamethus' head so that the king couldn't identify his body. And even though Trophonius hates Apollo, Apollo still is shown to love his son, and has some guilt about how it happened, even if what he did was what he, at the time, thought was best, since Trophonius had already done something illegal and wanted to be bailed out.
Hal's situation is similar, yet polar opposite, of Trophonius'. Hal, too, went against what was expected of them, but Hal's, unlike Trophonius' was for the betterment of another, rather than himself. Yet Trophonius' "curse" is consequences without divine intervention: if he had any mortal parent, he would have suffered the same fate. Hal's is, at it's core, a byproduct of being Apollo's son. No other parentage could have led Hal to his fate, and it is truly a curse, no if, ands, or buts.
Hal knew Apollo as a child, this much is evident from the aforementioned quotes. Apollo had warned Hal of his fate as a child, and the dangers of his powers. He told him if he shared it would anger the gods. Not him, the gods. It's curious wording. While Apollo is a god, if he was refering to himself, would it not be more striking to say to Hal that telling the future would anger me? Why envoke the other gods at all if he's going to be the one to enact the punishment?
Curiously, which I've never seen mentioned before, is the timeline. While Rick Riordan's years are wonky, Hal is approximately 60 years old, or looks at least. While he doesn't know how long he's been locked away, it has been decades at least. Luke is 14, Thalia's 12, and Annabeth (and by extension Percy) are 7. Beryl is an 80's actress, which makes sense timelinewise if Percy and Annabeth are 12 approximately in 2005, placing the date of the encounter with Hal at around the year 2000. Hal, therefore, was born after World War 2, and therefore after the oracle speaking of the Great Prophecy and Hades cursing the oracle because of Maria's death. In fact, Hal's childhood had to have been within ten to fifteen years of the curse, which for gods is a blink of an eye. The gods are especially apprehensive about prophecies and the future now with this great prophecy looming over their head. Apollo knew the other gods would not be favorable to a child of his with prophecy powers, and wanted Hal to lay low, especially since he already had a cursed oracle recently. This could be a longshot, but it's worth noting nonetheless. It shows the other gods have motive to distrust prophecies when Hal was a child.
Back to Apollo, throughout the five books in his POV he never, once, mentions Hal Green, even when speaking about Trophonius and having a child who hates him, even when thinking about his father and his own experience with fatherhood, even when thinking that his children don't deserve him and that he could be a better father. Halcyon's curse was brutal, yet Apollo never mentions his name once. He speaks of Zeus' punishments for disobeying, but never once mentions or wrestles with the idea that a son of his is stuck luring children to their death, wearing the shedded skin of Python, and only able to talk through leucrotae? And was stuck there for decades? Is that not odd, and honestly out of character given how much he tries to do better by his children than his father does to him?
Of course, a reason could be that Rick Riordan forgot about Hal, but where is the depth in that? To me, it is more interesting if Apollo had no say in the punishment of Hal. If it was more a punishment for himself, than it wouldn't be something for him to feel guilt about.
Now, if it wasn't Apollo, who do I think was the one who cursed Hal? To me it is pretty clear: Zeus. Zeus is apprehensive of prophecies: he ate Metis because he was told a son of his and Metis would overthrow him, he refused to sleep with Thetis since her son was said to be stronger than his father, and he'd recently made a pact to have no children and attempted to kill Bianca and Nico on the off chance that the Great Prophecy referred to them. If Hal could forsee the fall of Zeus without being an oracle himself, that was a threat to Zeus.
And besides, Zeus has no apprehension about killing his grandchildren; he murdered Asklepios for his continous raising of the dead. And Hal is kind of doing the same thing? Saving a person from death.
Since Hal thinks Apollo is the one that punished him, Zeus couldn't have outright done it if it was him which leads me to the least concrete part of this theory, as I see there being two possibilities:
Zeus took the form of Apollo when he cursed Hal
Zeus forced Apollo to curse Hal himself
Let's start with the first one: Zeus is obviously physically capable of turning into Apollo, gods can appear as any form they'd like. And as for why, I find that pretty straightforward. Zeus doesn't want people to know it's him. Despite being scared of prophecies, Zeus is the king of the gods, he is the god of gods and men, he is the strongest being. He doesn't want people to think that he felt threatened by a little boy, much less Hal himself. Appearing as Apollo gives the allusion that Apollo is angry with Hal for disobeying him, and gives the other gods the allusion that Apollo is enacting justice because someone, not an oracle, is using prophecy. This is what I mean when I said earlier that the "Apollo" in the story from Hal may not have been Apollo 100% of the time.
Also, is it not odd that Zeus' aegis, something that can only be claimed by a child of Zeus, was locked away in Hal's house? That cannot be a coincidence. The leucrotae are guarding Zeus' treasure, not Apollo's, Zeus's.
For that second point, it's basically that Zeus had manipulated Apollo into believing that he had to punish Hal or else it would be worse for him. Given Octavian, it's clear Zeus has no qualms about punishing Apollo for his children/descendants failures. Zeus also probably would tell Apollo he could never tell Hal the actual reason for the punishment.
I personally believe the most likely is that Zeus did the physical cursing: the python skin clothes, the missing voice, and the quarantine, while Apollo delivered the leucrotae under manipulation. I believe I doubt that Zeus would fully trust Apollo to enact the punishment exactly how he wants and not soften it for his son, and giving the leucrotae would still let Apollo see the punishment and feel the pain while not being able to mess up the plan.
As for Hal's epiphany about why he was punished, wouldn't it be interesting if he saw Apollo's fate of the wars in Thalia's vision? That he saw her helping a mortal Apollo punished for a child's crime? Yes, he also saw Luke working for Kronos and that scared him, but maybe there was also something about Gaea and Octavian too.
There's two ways Hal could have interpreted this: one, he realized that Zeus punished him but didn't want to say it because Luke already was planning a coup, or two, he thought Apollo punished him because if he didn't Apollo's punishment would be would be so much worse.
I've been typing for over an hour and a half with the breaks only to find the books and quotes so I'll leave it at that for now. Fingers crossed it's coherent.

















