Fourth Floor Pictures

Errol Morris interweaves the stories of four men, each driven to create eccentric worlds from their unique obsessions, all of which involve animals: a lion tamer shares his theories on the mental processes of wild animals; a topiary gardener devotes a lifetime to shaping bears and giraffes out of hedges and trees; a man fascinated with hairless mole rats; and an MIT scientist who has designed complex, autonomous robots that can crawl like bugs.

Documentary filmmaker Errol Morris investigates the case of a man who became an authority on capital punishment, but was discredited when he got involved on the wrong side of a court case. Leuchter, a meek man whose appearance belies his grim expertise, develops what he says is a more effective electric chair. Before long, he's in demand from officials who want his opinions on other execution methods. But when called to aid the case of an accused Holocaust denier, Leuchter's problems begin.

Prequel film to the Dead Body Man series