The policeman stepped back a little, and flattened himself—­comparatively speaking—­against the outer wall of the hostel itself.  There followed a silence.

Suddenly, without any warning, a heavy body, discernible a moment later as a small carpet-bag, filled to bursting, fell abruptly on to the pavement; and, again, a moment later, two capable-looking hands made their appearance, grasping with extreme care the central rod on which the spikes were supposed to revolve, on either side of the saddle.

Still the policeman did not make any sign; he only sidled a step or two nearer and stood waiting.

When he looked up again, a young gentleman, in flannel trousers, gray jacket, boots, and an old deerstalker, was seated astride of the saddle, with his back to the observer.  There was a pause while the rider looked to this side and that; and then, with a sudden movement, he had dropped clear of the wall, and come down on feet and hands to the pavement.

“Good morning, officer!” said the young gentleman, rising and dusting his hands, “it’s all right.  Like to see my exeat?  Or perhaps half a crown—­”

(V)

About six o’clock in the morning, Jack Kirkby awoke suddenly in his bedroom in Jesus Lane.

This was very unusual, and he wondered what it was all about.  He thought of Frank almost instantly, with a jerk, and after looking at his watch, very properly turned over and tried to go to sleep again.  But the attempt was useless; there were far too many things to think about; and he framed so many speeches to be delivered with convincing force at breakfast to his misguided friend, that by seven o’clock he made up his mind that he would get up, go and take Frank to bathe, and have breakfast with him at half-past eight instead of nine.  He would have longer time, too, for his speeches.  He got out of bed and pulled up his blind, and the sight of the towers of Sidney Sussex College, gilded with sunshine, determined him finally.

When you go to bathe before breakfast at Cambridge you naturally put on as few clothes as possible and do not—­even if you do so at other times—­say your prayers.  So Jack put on a sweater, trousers, socks, canvas shoes, and a blazer, and went immediately down the oilcloth-covered stairs.  As he undid the door he noticed a white thing lying beneath it, and took it up.  It was a note addressed to himself in Frank’s handwriting; and there, standing on the steps, he read it through; and his heart turned suddenly sick.

* * * * *