In an appended note Roach attests to the authenticity of her 18th-century London background, and a few historical figures wander through the story--most notably, there is a stay at Hugh Walpole's Strawberry Hill. But none of this obtrudes in what is essentially the story of the terrier and his humbler human friends. It begins when a poor, traveling puppeteer sees the dog in the turnspit at an inn and gives him a pitying glance and a name. The name as much as the glance charges Presto's spirit, and soon he has escaped the inn and found freedom, hard knocks, and hunger on London's streets. Again he runs into Dick the puppeteer, is recognized, and more or less adopts the human. Then, between adventures--Presto is twice kidnapped by a fiercely disciplined band of Revolutionary anti-human dogs and once captured by a drunken human for use in vicious rat-and-dog fights--Presto lives happily with Dick and a community of performing friends (human and animal) at the inn of kindly Mrs. Lightfoot, a former wrestler. There the animals function as a sort of backstage chorus, discussing and participating in the humans' affairs (a waif's adoption, a pickpocket's threat), and Presto wins his keep and a share of glory as a feature in Dick's Punch and Judy show. He proves a winning performer on and off-stage and an alert, entertaining observer of 1760s London.