 O 'Malley notices " the arsenal , " a stone building near the Forrest mansion which served as Robert Forrest 's office and library . One afternoon , O 'Malley observes smoke rising from the arsenal 's chimney . When he asks Kerndon about the building 's purpose , Kerndon ( who cannot see the smoke ) tells him it is only a storehouse . O 'Malley slips away to investigate . He discovers Christine burning what she claims are love letters , but he suspects otherwise . Later , Kerndon telephones somebody and assures the unnamed party that he will take care of the situation . As O 'Malley learns more , he begins to wonder if Christine and her cousin Geoffrey Midford ( Forrest Tucker ) are lovers and murderers . However , Geoffrey 's announcement of his engagement to Rickard 's daughter , and Christine 's reaction , discounts that theory . 
