This is a book that takes you a long way down a certain road, and then takes a sharp left turn, after which you see the road you just traveled down in a new light, and it’s not a good one. I can’t think of another book that operates in quite the same way. My oldest kid recommended the book to me and made the observation that at the end of the day, it’s clear why the writer made the choices she did—there was probably no other way to do it—but still, you feel thrown for a loop at the end. A bit swindled. But in exactly the same way the writer was swindled. So you not only get it, what she’s trying to say, you feel it.

I don’t want to ruin the effect for anyone who would like to experience this sort of whiplash for themselves, so I will speak broadly.

The book at first presents as the type of memoir where the author becomes fascinated with a little- known historical figure, in this case the taxonomist David Starr Jordan, and finds interesting parallels between the historical figure’s life and work, and her own contemporary ambitions and struggles. (This is somewhat how Helen Macdonald’s wonderful H is for Hawk operates.) The book’s ultimate success depends on at first believing in Starr Jordan and his merits—he worked doggedly, identifying a full fifth of the fish known to man, and kept working even when his research was destroyed multiple times. Starr Jordan’s curiosity and work ethic indeed seem heroic at first. But then there’s that turn.

There’s a lot of interesting research here—you’ll walk away knowing more about how species are classified, among other things—but in the end, the real lesson here is that we shouldn’t be too sure of what we know, and must be careful of the line between being right and that particular brand of righteousness that can prove so dangerous.