Colette, Violet, Pamela, Nicky, and Paulina are the Thea Sisters at Mouseford Academy; they study with Thea Stilton, journalist and equally famous sister of the famed Geronimo Stilton. The new school year brings new students, including siblings Vanilla and Vic, children of wealthy businesswoman Vissia De Vissen, who claims to be concerned about the environment. When an orca threatens the local fishermen, however, the Thea Sisters discover that Vissia has plans for the orca and other sea creatures, including the whales of Whale Island, that bode no good for the environment. Thea Stilton is credited as the author, but the story was created by a team of Italian writers and artists and translated by Nanette McGuinness for Papercutz. The story centers on the Thea Sisters rather than on Thea Stilton, who makes only a brief appearance in this book, but most readers won't care. They'll enjoy the action and mystery in this colorful graphic novel. Fans of the chapter books will also enjoy the additional adventures in this new series.

In their first graphic novel, the Thea Sisters (five mice students who aspire to be journalists), look into a whale's odd behavior and the disruption of a Mouseford Academy ritual. Advanced language and an extensive back story from a related series make a poor starting place, but the illustrations' light, warm palette and a style reminiscent of classic adventure comics make this story appealing.