A drive train for a motor vehicle is provided. The drive train includes a heat flow generating drive motor, a steam engine in a steam circuit, and an evaporator. The evaporator has an inlet for liquid working fluid and an outlet for evaporated working fluid. The evaporator also includes an auxiliary outlet, via which a portion of the heated working fluid is guided through the inlet into the first evaporator and is discharged with the heat flow, before the residual working fluid in the evaporator is further evaporated by means of the heat flow.