The movies have taught us to fear mad science, when it's really bad science we should be afraid of. And Project Nim, the new documentary from Man on Wire director James Marsh, examines some of the worst science you've ever seen. In the 1970s, a professor named Herb Terrace enlisted a family to raise a chimp named Nim Chimpsky as though it were a human baby. When that didn't work out—faces were bitten—he took the chimp to a New York farmhouse and continued experimenting with sign language, even as Nim brutalized the assistants assigned to him. Eventually, Terrace closed the project down and sent the chimp off to institutional limbo. Heartbreak ensued.

The best—and freakiest—part of Project Nim is Terrace's willing involvement in the film. In a series of defiant interviews, he stands by his science and ethics even today. You suspect that he probably has to; his huge ego won't allow him to believe he could be in the wrong. Trying to defend his failed experiment, Terrace even goes so far as to attempt to discredit the chimp rather than himself—insisting that Nim's sign language did not count as real language. He says it was just highly specialized begging. (What, exactly, does he think language is, then? How much of what we humans say every day, when you get right down to it, is highly specialized begging over resources?)

Project Nim is a tough movie to watch, but that's just because it's willing to take a stand. Nim's story evokes a palpable sense of moral outrage (and a very identifiable sense of hypocrisy) in its viewers. The first half will make you want to bring a baby chimp into your own living room; the second half will fill you with rage that anyone could ever believe that would be a good idea. It's a sharp, well-told story that infuriates and fascinates in equal measure.