Subway Out of Control!

The gang arrives in New York. Pai, left alone with the luggage, is hustled by a clever thief and they're left without luggage or money, so they take shelter in a cheap motel. Jacky blames Pai for being careless with the luggage, and she gets fed up and storms out of the motel. Akira finds Pai in the city and tries to comfort her. Then they save a defenceless boy names Jimmy who was being harrassed by thugs. They take Jimmy back to the motel, where he tells Jacky that he knows where Sarah is. Jimmy takes everybody back to his apartment just in time to see a bunch of thugs carry Jimmy's sister and (could it be?) Sarah to the subway. The gang chase them and hop a ride onto the subway. There, they meet up with Kruger, a skilled martial artist, and Akira makes short work of him. Kruger confesses where Sarah is going, but then he manages to escape. They follow him on foot through the subway only to discover his body! Who could have killed him?