Mugging

She found it just as Sam got the man he was fighting down on the ground and climbed on top of him.

She hurriedly dialed the police and the hospital before crawling back to Xiao Hai and pressing on his wounds, all the time asking him to stay awake.

Sam had punched the man unconscious and was getting up when he received a sudden punch in the stomach. Yu Chen looked up with a start to see the third man, the man Xiao Hai had originally punched, now beating up Sam. And Sam, who had been taken unawares, couldn't do much except defend himself.

Chen looked around in despair, hoping to find something, anything that would help her. It was then that a sudden idea came to her. Chen stood up and ran towards her backpack that she had dropped when all the ruckus had started. She opened the backpack with trembling fingers, fumbling with the zipper a few times. She finally got the bag open just as the mugger began to overpower Sam.

Yu Chen turned her face towards the two locked in combat for a split second before she pulled her attention back to her bag, and grabbed what she was looking for. 

Sam had been sufficiently proud of himself beating that one man unconscious. Sure, he had taken him by surprise, but the man was twice as heavy as him, and strong besides. Just as he stood up to look at Chen and the other man he had saved, Sam grunted and doubled-over in pain.

Sam had his hands up to cover his face as he lay on the ground and was showered with punches, a few kicks thrown in for good measure. He was a good fighter, better than most, his years of self-defense lesson had made sure of that. But this man was bigger than him, had taken him unawares, and had probably had much more experience actually fighting people than Sam. Sam racked his brains for ways to pull himself out of this situation, but he didn't have to think long. He heard a loud thud just behind the man atop him, and before Sam had time to react, the mugger had fallen on him.

Sam blinked in confusion a few times before he realized that he was suffocating beneath the huge man, and decided that he needed to be able to breathe to figure out what had happened. He pushed the unconscious man off to see Yu Chen standing right in front, something black and broken in her hands.

Chen panted as she saw Sam struggle free of the man's weight and look at her. Her mind snapped into action a little delayed as Sam began to struggle to stand. She moved to help him, but Sam shook his head, pointing towards Xiao Hai. Chen nodded and rushed back to him, discarding her broken weapon along the way.

Sam stooped down, wincing in pain and picked up the black thing Chen had used as a weapon. He stared at it for a few seconds before he looked up with a shocked expression. "Chen. . . . ?" he called out.

"Yes?" Yu Chen didn't even look up, she was busy trying to stop Xiao Hai from bleeding to death.