On an abandoned farm where a double bloody murder was committed many years ago, the corpse of a young girl, strangled more than thirty hours ago, is found under a heap of rags. Detective Jess Campbell established that on the day the body was discovered, a silver Mercedes unknown in the area was speeding along the road from the farm. If there was a killer in it, then why did he return to the farm after so much time, and if this is an important witness, then he is in mortal danger. In any case, the owner of the Mercedes must be found as soon as possible...