Savary, aide-de-camp to the First Consul, prepares for his boss's visit to Strasbourg. The police arrest Joliet, a courier for the émigrés, who confesses the purpose of his mission: to make contact in the city with a certain “schoolmaster.” The problem is that there are 150 Schulmeisters (schoolmasters) in Strasbourg. One of them is a suspect because he is a former smuggler. The courier Joliet recognizes him in order to save the real one, but he proclaims himself a Bonapartist and offers to find the real culprits himself. Savary agrees and organizes a fake escape. With Hammel, one of his friends, Schulmeister infiltrates the heart of the conspiracy and recognizes the man giving the orders: his own cousin, Neubacher, the real “schoolmaster.”

Schulmeister's first official mission: to find a valuable agent in England whose life is believed to be in danger and bring her back to France: the Countess of Fréville. Schulmeister's wife, Suzel, is less than enthusiastic and finds that her husband, who had always been a quiet man, is embarking on a very strange undertaking. In fact, the adventure gets off to a bad start. Instead of kidnapping the real countess, Schulmeister is duped and brings back to Paris a certain Arabella, known as “Petit Matelot,” a French woman who has gone over to the service of the émigrés. The real countess is taken to the Tower of London and sentenced to death. Unmasked, Arabella flees, and Fouché, who is fighting against Savary's parallel police force, scores a point. Arabella has infiltrated the empress's laundresses at La Malmaison and is sending messages to her leaders. How can they be intercepted? It is Schulmeister's wife who one day has the idea of taking a closer look at Arabella's embroidery...