Bavaria, 1776. When Albrecht Durer the Much Much Younger's Frog Prints go missing, he knows exactly where to turn for help. Gretel (yes, that Gretel), now 35 and still living with her gluttonous brother Hans, is the country's most famous private investigator, and she leaps at the opportunity to travel to cosmopolitan Nuremberg to take on the case. But amid the hubbub of the city's annual sausage festival, Gretel struggles to find any clues that point toward the elusive thief.

Even with the aid of the chatty mice living under her bed, the absent prints remain stubbornly out of view, and Gretel is forced to get creative in her search for the truth.