In this paper, we propose a new method for simulating reactive motions for motion capture animation. The goal is to generate realistic behaviors under unexpected external forces. A set of techniques are introduced to select a motion capture sequence which follows an impact, and then synthesize a believable transition to this found clip for character interaction. Utilizing a parallel simulation, our method is able to predict a character's motion trajectory under dynamics, which ensures that the character moves towards the target sequence and makes the character's behavior more life-like. In addition, the mechanism of parallel simulation with different time steps is flexible for simulation of multiple contacts in a series when multiple searches are necessary. Our controller is designed to generate physically plausible motion following an upcoming motion with adjustment from biomechanics rules, which is a key to avoid an unconscious look for a character during the transition.