"When Spinelli comes back to this room, you will be informed that neither you nor your constable will be needed further tonight. Both of you will leave here, ostentatiously…" "Ah! And follow Spinelli?"
"Tut, tut, Nothing of the kind. Those uniforms of yours would be spotted half a mile, especially if Spinelli has reason to believe he is under surveillance. The constable will go home. You, after pretending to do so, will take a long way round and go to the Guest House. This is merely a guess of mine, but we shall have to play a long chance."
Murch stroked his moustache. "But there's nobody at the Guest House, sir! You be and sent the man Storer away to the 'Bull'—"
"Exactly. You won't go inside, but keep in concealment close to the house, and watch what may happen. Meanwhile…"
He turned to Hugh Donovan, and smiled quizzically. "You look like a stout young fellow who could take care of himself if it came to trouble. So I’ll tell you why I wanted you here to listen to what we've heard tonight. You've — hum — studied academic criminology, they tell me." He coughed meaningly, and as Hugh met the glance over the doctor's spectacles he knew that this fat bandit knew his own particular guilty secret. "Would you like to try a little practical work?"
"Would I!" said Hugh fervently.
"Think you could follow Spinelli wherever he went, and keep out of sight?"
"Absolutely."
"I don't like to do this, but you're the only person here who might conceivably do it. And before you agree, I want to impress on you exactly what you're doing." Dr. Fell looked sharply at him, at the bishop, and at the scowling Inspector Murch. "If I'm right, you see, that man Spinelli is going to walk straight into a death trap."
He waited to let that statement sink in, and for his listeners to use their imaginations on it. The bright, hot library had become full of suggestion.