Nick Knight and Janette have come to Peggy Bolger's house in order to try to save Janette's ward and his aunt, who have been captured and tied up by a pair of arsonists. However, once they have provided the men with the key to the locker where evidence has been stored, the men do not simply leave. Instead, they shoot Nick and Janette. The men then detonate a bomb in order to destroy any evidence in the house.
The bomb consists of a small explosive attached to a bottle filled with inflammable liquid. It has been set by a window in an inconspicuous location; and neither Nick nor Janette has spotted it. One of the arsonists detonates it with a remote device as the pair of them are leaving the house.
Fortunately, being a vampire, Nick has not been injured by being shot. Even as the fire quickly spreads, he is able to free the prisoners so that they can escape.