couple were driving on an isolated road.
Unfortunately, the automobile ran out of gas.
The husband decides to leave his wife in the car while he walks to the nearest gas sation.
His wife stays in the car.
She locks the doors and rolls up the windows.
Upon the husband's return, he finds his wife's dead body in a pool of blood.
Another person is inside the car, near his wife's body.
The windows are still closed and the doors are locked.
Question: What happened?