ring vs zombies

I looked back again and saw Dead Phil clinging to the back of the car. He had to have been standing on the rear bumper. The other three dead men weren't far behind him, keeping up with the car. Dead Phil drove his hand down at the back of the Beetle, and there was a wrenching sound of impact, then a series of snaps and squeals as he tore the back cover from the car, exposing the engine.
"Take the wheel!" I shouted to Butters. He reached over and seized the steering wheel. I twisted and thrust my right hand at Dead Phil. I focused my attention on the plain silver ring on my middle finger. It was another focus, like the shield bracelet, one designed to store back a little kinetic energy every time I moved my arm. I focused on the ring, clenched my hand into a fist, and shoved it directly at Dead Phil, releasing the energy within.
Dead Phil had raised his arm again, this time to tear apart the Beetle's engine, but I beat him to the punch. The unseen force unleashed from the ring hit him at the top of his thighs, kicking his whole lower body out straight. The force tore his grip loose from the car, and he tumbled away, hitting the street with heavy, crunching sounds of impact, arms and legs splayed. The other dead men ran past him, one leaping clear over, and Dead Phil lay twitching on the ground like a broken toy.


Dead Beat Chapter 5, page 46