Beneath librarian Angus McAslan's respectable demeanor thrums the heart of an adventurer. He dreams of traversing the globe, exploring ancient ruins, and discovering amazing scientific breakthroughs. And unbeknownst to even his dear devoted mother, he's just put the finishing touches on his own epic novel about a swashbuckler on Venus—complete with illustrations! But after inadvertently reciting a summoning spell, Angus finds himself thrust into an adventure beyond even his own wildest imaginings.

Suddenly, demon-possessed pupils try to kill him. Half-human creatures stalk him. His mother reveals herself as a witch, and his wizard uncle proclaims it high time Angus join the family business. Complicating matters: the exquisitely handsome young man—bearing an uncanny resemblance to the aforementioned Venusian swashbuckler—sent by his uncle to collect Angus, and the suave, aristocratic warlock who materializes with dire warnings of a resurrected Elder God called Janus.