Tragico carnevale

During their return trip to Darkwood, Zagor and Chico arrive in New Orleans, Louisiana, which recently become an American territory, exactly on time when Mardi Gras (final day of carnivale) is about to begin. But the celebration soon turns into tragedy: Donovan, the commander of the city's military garrison, is murdered in cold blood during the float parade. And the main suspect is actually Chico!