“Where’s damn marble?”
“Here, sir.”
“Call out when she moves, right? North, south, whichever way she rolls. Understand?”
“Yes, sir.”
“Know which way’s north?”
“That way,” said Roach promptly, and stuck out his arm at random.
“Right. Well, you call when she rolls,” Jim repeated, and disappeared into the rain.

— John le Carré, Tinker, Tailor, Soldier, Spy