France, 17th century, under the reign of Louis XIII. Dogtanian is an impetuous and innocent peasant from Gascony, as well as a skilled swordsman, who travels to Paris with the purpose of making his dream come true: to join the Corps of Muskehounds of the Royal Guard.

Having been demoted for failing to prevent the murder of one of his superiors, Mondo is startled by a group of masked thugs who are soon attacked in turn by an unseen force. He begins to suspect the work of assassins, but whose side are they on?