"I don't know, sir, yet. You've come just in time. Waverley is missing.
"Waverley missing! That's nonsense. He was put on to relieve Norman in shadowing Ivan Abramovitch."
"He's missing," repeated the other doggedly. "Ivan went into a shop with an entrance in two streets, and the man who was assisting Waverley slipped round to the other side. He waited there an hour, and then went to look for Waverley."
The superintendent gave a short, contemptuous laugh.
"Green, I guess you've been working too hard lately. You ought to apply for a fortnight's leave. Can't you see, Ivan came out and that Waverley never had time to give the tip to his man, but followed him straight away? There ought to have been three men on the job."
Green drew himself up stiffly. Foyle had not recovered from the irritation caused by his own mistake, otherwise he would not have spoken as he did. Green was not the kind of man to hastily jump to conclusions.
"A third was not available when Waverley left," he said. "Here is why I say Waverley is missing. It came by messenger five minutes ago, addressed to you. As senior officer I opened it."
Foyle took a typewritten sheet of paper from the other's hand. It read simply—
"Dear Mr. Foyle,—You had better call your men off. We have got one of them safe, and hold him as a hostage for our own safety. If your people go on trying to make things unpleasant for us, things will get unpleasant for him. This is not melodrama, but brutal fact."