That final subway twist in 'One Last Stop' floored me. The whole book builds on this sweet, funny meet-cute between August, a cynical new-in-town girl, and Jane, a magnetic but strangely old-fashioned girl she keeps running into on the Q train. The central puzzle is why Jane seems perpetually stuck in the 1970s, can't leave the subway, and has these huge gaps in her memory. August becomes obsessed with figuring out who Jane really is and how to free her from this weird temporal loop.
It's less a traditional whodunit and more a 'how-do-we-fix-this' mystery wrapped in a love story. The investigation leads them through New York City's queer history, punk archives, and old protest flyers, trying to piece together Jane's past life as a Chinese-American activist and artist from the '70s. The solution ties into a specific, real historical event, which makes the emotional payoff hit so much harder than just a random supernatural glitch. I loved how the mystery wasn't just a plot device but became the engine for August to build her own chosen family in the city.