A plain and unattractive girl named Jennifer Murdley encounters the Magic Shop and is given a wisecracking talking toad, Bufo, who gradually reveals his complicated history and its relation to a growing danger in the present and the secrets about the magical, mystical Jewel of Perfect Happiness in his forehead.
The Greek goddess of strife Eris breaks into the Magic Shop while Mr. Elives is away and gives the shy but acid-tongued Juliet Dove a crystal amulet containing Cupid that causes every boy she meets to become truly, madly and strongly in love with her.
With Elives himself unsure of what to do, Juliet is forced to team up with the rats Jerome and Roxanne to prevent Eris from causing worldwide discord and chaos.
Short stories about Elives' Magic Supplies store have appeared in Coville's Oddities anthology books.
[11] Publishers Weekly later wrote a mixed review for The Skull of Truth, stating "Though the tale itself is lackluster, Coville does keep readers engaged with tight plotting and an otherworldly climax.