"Yes. The car will be here directly. There's a letter I must write first." He sat down at a writing table, and took out a sheet of notepaper.
He was facing the secret door; if it opened he would see it. At any moment now it might open.
Bill dropped into a chair and thought. Antony must be warned. Obviously. But how? How did one signal to anybody? By code. Morse code. Did Antony know it? Did Bill know it himself, if it came to that? He had picked up a bit in the Army—not enough to send a message, of course. But a message was impossible, anyhow; Cayley would hear him tapping it out. It wouldn't do to send more than a single letter. What letters did he know? And what letter would convey anything to Antony?.... He pulled at his pipe, his eyes wandering from Cayley at his desk to the Reverend Theodore Ussher in his shelf. What letter?
C for Cayley. Would Antony understand? Probably not, but it was just worth trying. What was C? Long, short, long, short. Umpty-iddy-umpty-iddy. Was that right? C yes, that was C. He was sure of that. C. Umpty-iddy-umpty-iddy.
Hands in pockets, he got up and wandered across the room, humming vaguely to himself, the picture of a man waiting for another man (as it might be his friend Gillingham) to come in and take him away for a walk or something. He wandered across to the books at the back of Cayley, and began to tap absent-mindedly on the shelves, as he looked at the
