"Then no taxi will avail us," groaned Jimmy, "and I must call for a liqueur brandy instead. . . . Oh, Otty--you must forgive the old feud: but why _did_ your parents send you to Cambridge? Mine sent me to a place where I had at least to sweat up forty pages or so of a fellow called Plato. Not being able to translate him, I got him more or less by heart. Here's the argument, then. . . . Supposing a friend makes a deposit with you, that's a debt, eh? Of course it is. But suppose it's a deposit of arms, or of money to buy arms, and he comes to you and asks for it when he's not in his right senses, and you know he's not, and he'll--like as not--play the devil with that deposit, if you restore it. What then?" "If I thought that Farrell was in danger," I mused; "that's to say, in any immediate danger--" "Rats!" said Jimmy contemptuously. "Farrell's a third party. Why drag in a third party? The Professor's _your_ friend; and he's made a deposit with you: and you don't need to think of anyone but him. For he's _mad_. . . . Now, come along to the smoking-room, where I've ordered them to take the coffee, and where I'll give you ten minutes to pull up your socks and do a bit of thinking." "Maybe you're right, Jimmy," said I as we lit our cigarettes. "And if so, it's pretty ghastly. . . . He's had enough to put him off his hinge. But somehow I can't bring myself--No, hang it! I've always looked on Jack as the sanest man I've ever known. If he has a failing it's for working everything out by cold reason." "Just what he's doing at this moment," answered Jimmy dryly. "If you don't like the word 'mad' I'll take it back and substitute 'balmy,' or anything you like. Madness is a relative term; and I should have thought that what you call working-everything-out-by-cold-reason was a form of it. I know jolly well that if I felt myself taken that way I should go to a doctor about it. And if _you're_ going to practise it on the subject just now before the committee, I shall leave the chair and this meeting breaks up in disorder." "The point is," said I, "that the letter has gone." "What address?" he asked pouring out the coffee. "Biarritz, Grand Hotel--Why surely you read it?"--I stared at him, but he was looking down on the cups. Then of a sudden I understood. "Jimmy," I said humbly, "I've been an ass." "Ah," said he, "I'm glad you see it in that light. . . . The afternoon mail has gone: but there's the night boat. You can't telegraph, unfortunately. In his state of mind you mustn't warn him. You must catch him sitting." "Look here," I proposed. "It will be a nuisance for you, Jimmy--it will probably bore you stiff. But if you'll only come along with me . . ."