"Now that the terrible Toney Sludge has escaped from prison, it's up to Geronimo Superstilton and the Heromice to defend Muskrat City from the notorious Sewer Rats and stop an enormouse blackout! Will our heroes be able to defeat their enemies without losing their fur?" -- back cover.

"Original title: Fermi tutti, superscamorze in arrivo!"--Title page verso. Translated from the Italian. "Appeals to 2nd - 4th graders" -- back cover. "Reading level Grade 4" -- back cover.