Escapement mechanism (3) for a watch movement including a pallet lever (7) with a fork (13) and a roller device (4) with an impulse-pin coupled to a balance (2). The fork includes an entry horn (19) and an exit horn (21), the impulse-pin including a first cam portion (12a, 12b) configured to engage the entry horn, and a second cam portion (14a, 14b) configured to engage the exit horn. The first cam portion includes a first cam surface (12a) configured to engage the entry horn on a first level (10a, 10b), and the second cam portion includes a second cam surface (14b) configured to engage the exit horn on a second level (10b, 13b), the first and second levels being staggered in a direction parallel to the axis of rotation (A) of the roller device.