Things that go *THUMP* in the night

The night was going from bad to worse. The quiet thumping in the back had stopped when they parked. Summer held her breath as the glow of the police cruiser's headlights turned on to the street. Slowly it moved down the road until it had passed by their vehicle. She didn't think they had even parked somewhere well hidden, but the cop car just drove on by at an agonizing snail pace.

Summer mumbled in a quiet whisper as the police car passed by them. "I think he's still alive in the trunk! Go back there and look! Gods, what if that cop car turns back around again?!"
 
With a dry swallow and a shallow nod he drew the key out of the ignition as if any sudden movement would cause the patrol car to turn around. Then opening the door ah got out his shoe crunching in the gravel on the side of the road. He looked after the police one last time and began the agonisingly long walk to the back of the car listening for any movement from inside.

With the soft crunch of gravel the car started to roll down the shallow slope gaining speed and on a second Richard found himself next to nothing but open air. "Summer!" he called out starting after the runaway vehicle.