"Sorry," said Colin penitently. "The fact is, I've got a very urgent appointment with Inspector Marsden. He telephoned me to be here at a quarter past without fail." "Well, you take my advice and be a bit more careful the next time," observed his interrogator, "or as likely as not you'll find yourself in trouble." He turned to his companion. "Better take him up at once. The Inspector's in his room." Climbing out of the car and following his guide, Colin ascended the flight of stone stairs until they reached the same apartment to which Marsden had conducted him before. Having inquired his name, the constable rapped loudly, and in answer to a peremptory invitation pushed open the door and stepped briskly forward. "Doctor Gray to see you by appointment, sir." Marsden blotted the letter that he was writing and got up from his desk. "Come along in, doctor," he called out; and then, as Colin entered, he pulled forward a chair and motioned the constable to withdraw. "Take that seat," he added, directly the door was shut. "There's no time to waste, and I want to hear your story before we discuss anything else. Don't hurry, though; tell it me in your own way, just as you did when you described the murder." Colin laid his hat on the floor, and, thrusting his hands in his pockets, commenced to speak. In very much the same words that he had used to Mark he repeated the whole history of Fenton's relations with Nancy and himself, taking the utmost care to omit nothing which might have any conceivable bearing on the case. Then, still in the same methodical and detached fashion, he went on to relate the remainder of his story, while all the time the Inspector sat by in grim silence, his hard blue eyes fixed intently on his companion's face. "I don't know how it strikes you," observed Colin, when he had quite finished, "but Nancy and I have been chewing it over pretty thoroughly, and we both think that it would take a damn sight more than a mere fit of jealousy to make Fenton risk his neck. We feel certain that there must be something much bigger at the back of it all, but beyond that we're absolutely gravelled." Without replying, Marsden leaned forward and pulled open a drawer in his desk. He turned over some of its contents, and then, taking out an unmounted photograph, handed it to Colin. "Do you recognize that?" he asked. Colin sat up, with a sudden start of surprise. "Recognize it!" he exclaimed. "Of course I do. It's 'Spike' Cooper." "You're sure?" "Positive. You don't suppose I'd forget his infernal face?" He inspected the picture carefully for several seconds, and then passed it back. "Where did you get hold of this?" he asked. "It was sent to me three days ago by the Canadian police. Perhaps you would like to hear the letter that came with it." He dived into the drawer again, and produced an official-looking sheet of blue paper.