"A" wakes up in a new person every day. While he (I will use this pronoun for convenience, but really A has no gender) tries his best to live life as that person would, what happens when he falls in love and wants to finally hold on to something constant?

I fell in love with this story. Levithan made me believe in the possibility someone like A could exist, in large part due to the parameters immediately set forth. For example, A only transfers to someone the same 'age' and only travels far distances when the current person he is in does. This takes care of what would otherwise be glaring holes in the storyline. A also has his own set of rules which he has crafted over his 16 years of existence. Only when he meets a girl, Rhiannon (girlfriend of one of his incarnations) that he starts to break some of his own rules.

The story kept me on my toes throughout, and never drifted into sappy sentimentallity. I felt the ending was pitch perfect as well; neatly tied up, but with a glimmer of possibility that perhaps Levithan will pick up A's story in the future. I hope he doesn't. I enjoy creating my own future for this character.