Nadalind is probably the most accidentally red-stringed fictional couple I’ve ever seen. Way before they were intended to become love interests, the narrative kept connecting and intertwining them (starting with the very first episode):
Nick was the first Grimm she ever saw, and Adalind’s was the first woge he ever saw
Adalind was ordered to kill Nick’s Aunt Marie (1x01)
Nick had to protect her during a murder investigation (1x03)
Adalind was ordered to date and use Nick’s friend and partner Hank’s life as leverage for one of the Keys →
Adalind was forced to consume Nick’s blood—in a physically intimate way (1x17) →
She put his girlfriend in a magical coma (1x22)
Nick’s mother, Kelly, “killed” Adalind’s mother in a fight (really, Catherine just lost that fight) (2x02)
Adalind was protected by and slightly bonded with—unbeknown to both at the time—Nick’s mother
Kelly’s time with Adalind and her daughter, Diana, triggered her last memory with young Nick
Kelly, still unaware of their history, brought Adalind and Diana to Nick’s house (3x17) ->
“Maybe it’s not a coincidence that you brought Adalind and her baby back here to Nick. [...] Carl Jung, synchronicity [the ep’s title]. When two or more events aren’t necessarily causally related but are connected through meaning.” (Juliette)
Kelly let Diana keep her locket with young Nick’s picture (3x18)
Nick’s mom temporarily raised Adalind’s daughter
Nick and Adalind each depowered the other/took each other’s supernatural identity away, temporarily (1x17, 3x22) ->
and both for sympathetic reasons related to the other—Nick, to save Hank from Adalind’s spell; Adalind, to get her daughter back from the Royals, who Nick and the others let her believe Diana was with
Adalind was able to do so because of having Nick’s blood in her system from when he did so
Bonus: Nick’s Aunt Marie had been in a relationship with a Wesen, before she ended it to raise Nick. So the idea and recent precedent of romance between Grimm and Wesen(-related beings) had already been canonized, and with Nick’s own relative.
