Watch with a timepiece movement, a resonator mechanism, including a magnetic escapement mechanism including an escape wheel set including a magnetized track, with a succession of areas according to a scrolling period in which its magnetic features are repeated, each area including an increasing magnetic field ramp followed by a magnetic field barrier with an increasing field and of higher field gradient that that of the ramp, the track includes a continuous, closed magnetic layer over the entire periphery of the escape wheel set, of constant thickness and variable width, whose geometry defines these magnetic field ramps and barriers, this escape wheel set cooperating with a sprung balance via a pivoting magnetic stop member comprising a pole piece arranged to cooperate alternately with an internal track and an external track of the magnetic layer.