Impact of Evidence

AMONG THE hills of the Welsh borders a little group of farmsteads is isolated by snow and ice, then floods. Late one afternoon there is a terrible car smash on a cross-roads in these hills. Old Dr. Robinson is found dead in his big saloon, which, thrown off the road by the violent impact, has crashed down on to the steep hillside, now sodden with flood-waters. That was no surprise-the old man should long before have been prevented from driving, he was a menace on the roads.
But why was there a second body there back of Dr. Robinson's car?