Choose one enemy model in BtB with the activating model.
The activating model resolves a Melee Exchange against that model. It must allocate at least as many dice to Defence as to Attack, and if unable to do this (E.g. the model is Aggressive) then it may not attempt a Disengage Action.
If the Activating model successfully defends or ends the exchange, not in BtB with the chosen model, after the Melee is resolved, it may make a Walk up to its Move Statistic in inches, ignoring all models in BtB.