Cassius Doyle, an ancient being of immense patience, seeks to invade the pristine parallel world of Naywist after a two-hundred-and-fifty-year wait. His surly, feathery companion, Benedict Wormwood, is by his side as they seize an opportunity when the entrance to Naywist is compromised. Cassius must overcome numerous obstacles, including the Durward Estate's land, locked doors, guardians, and a particularly loathsome ferret named Ajax, to achieve his goal.

The premise sets up a classic battle between ancient evil and a protected world, with a focus on the protagonist's long-held ambition. The narrative appears to center on Cassius's cunning and the various tricks he employs to bypass defenses. The inclusion of a companion and a specific, disliked animal suggests potential for character interaction and added conflict. The story's progression will likely involve Cassius confronting and overcoming each obstacle in his path to Naywist.