As a final year Law student Gilbert Hastings and Lucille Dellow take a holiday job to renovate the Old Stone House in Arbor Valley. The owner of the Old Stone House, Elsie Leggat has moved into a rest home and has been persuaded to sell her house by a corrupt Nadine Norton. Nadine has a hidden motive for listing the old lady's house.
The Old Stone House produces a a surprise that results in a house fire and Gilbert being charged with murder.
Gilbert does not realise that both Gilbert and Lucille are in danger from a hidden killer.