In “Plautus: A Memoir,” Oleg is the “ornamental hermit” who owns Plautus for the first few decades of her life. The noble family who lives next door to the Tolstoys hires Oleg when he’s only 30 and forbid him from bathing and from speaking, aside from a single Latin phrase. Over time, Oleg goes mad. Plautus watches Oleg read voraciously about philosophy and history; most of what he reads has something to do with the relationship between tortoises and humans. Plautus decides to abandon Oleg for the Tolstoys when, in his 80s, Oleg becomes obsessed with Christianity, which Plautus believes is unfriendly towards tortoises.