As it turns out Laughton is on his way to hire the Checkmate team to find the individual in Chinatown he's looking for. But Anthony George and Doug McClure get maybe a bit more than the usual blank wall that Chinatown shows to outsiders.
The plot construction is a bit inferior and simple forensics that the villain should have been aware of, trap him. But Laughton plays his role with his usual relish and his scenes with the criminologist Sebastian Cabot have some real distinction.
This is an episode where one sits back and enjoys Charles Laughton and forgets the rather large plot holes and poor writing for this particular Checkmate.