Appearing close to the same time that Percy Jackson first hit bookshelves, The Shadow Thieves starts from the same premise: the Greek gods are real and have been continuing in their characteristic immortal ways for thousands of years, with results that now burst into the lives of twenty-first century adolescents.

While it never captured the attention that Riordan’s male protagonist did, The Shadow Thieves is arguably the more interesting. Ursu’s central figure is Charlotte Mielswetzski, a red-headed eighth grader who tries not to attract much attention and is excellent at lying. Joined by her much cooler mixed-race English cousin Zee (along with a wise and adorable kitten), Charlotte must figure out what is causing a mysterious plague among children on both sides of the Atlantic. Like Percy, Charlotte and Zee make a journey to the Underworld as part of their heroic quest (here the entrance is in Minneapolis’s Mall of America), and there they encounter monsters both familiar and novel.

The Persephone narrative infuses the storyline to some degree, entirely without suggestion of the rape at the center of the ancient myth. Persephone herself (bored by thousands of years’ worth of unwanted goo-goo-eyed attention from her husband) has a subversive role in the proceedings. But the central “mythological” figure in the book is invented: Philonecron, a lower-level functionary in the massive bureaucracy that has developed through the centuries under Hades, is launching a plot to take power in the Underworld. The plague affecting Charlotte and Zee’s friends is the human cost of this plot, and the cousins must find a way to stop it.

Ursu’s narrating voice is snarky and creative, and while the Underworld, flickering with threatening shadows, can be a creepy setting, the novel’s humor and focus on Charlotte and Zee’s more mundane struggle with social and romantic problems counteracts the potential for scariness. While this story is self-contained, it is also the first of a trilogy called the Cronus Chronicles for readers who enjoy Charlotte and Zee here. - Clara Hardy