That done, the master sleuth returned to his former work.

Every detail was implanted in the mind of the master sleuth.

The Shadow's laugh indicated that the master sleuth knew the game involved more than a single individual.

It was inspired by the letters which this master sleuth had prepared.

The master sleuth had caught a glimmer of the game.

He was a master sleuth who moved by night, bringing disaster to men of crime.

Until he learned of its existence, the master sleuth would be working under disadvantage.

Until now, the master sleuth had entrusted the work to an agent.

Already, the master sleuth had passed along the corridor, beyond the door of Room 850.

The master sleuth was analyzing the situation which confronted him.