The Vault

Superintendant Chadwick gets 'koshed' over the head when he tries to enter the house where the latest three murders were commited. He didn't realise the the two constables that were supposed to guard the house had left to investigate the fire at Harry Day's cottage where they found Joe Hardy with paraffin. Chadwick believes that the fire was deliberately set to draw the constables away and allow the murderer to re-enter the house and retrieve some incriminating evidence such as the murder weapon. Back at the station they interview Joe Hardy who tells them that he was sleeping in Day's cottage when he smelled smoke. Running outside he saw a van, whose description matches that of Mr. Mitchell, leaving the burning cottage.