she coasted for a second and straightened up and then she hit the gas and the truck leapt forward , ten yards , twenty , thirty , and jacob duncan glanced back in horror and darted left , and dorothy coe flinched right , involuntarily , a civilian with forty years of safe driving behind her , and she hit jacob a heavy glancing blow with the left headlight , hard in his back and his right shoulder , sending the gun flying , sending him tumbling , spinning him around , hurling him to the ground .