During the Cologne carnival in Germany, Interpol inspector Tom Wilkins, master of disguise, hunts a band of jewelry thieves who haunt the cathedral square, disguised as beggars.

Policeman Tom Wilkins is the man of a thousand masks and disguises. He is pursuing a gang of fake beggars and real jewelry thieves who have chosen the city of Cologne as their field of activity. When a policeman disguised as beggars is murdered at the foot of the cathedral.