Detective Kosuke Kindaichi arrives on the remote Gokumon Island bearing tragic news - the son of one of the island's most important families has died, on a troop transport ship bringing him back home after the Second World War. But Kindaichi has not come merely as a messenger - with his last words, the dying man warned that his three step-sisters' lives would now be in danger. The scruffy detective is determined to get to the bottom of this mysterious prophesy, and to protect the three women if he can.