And in that moment he had a glimpse into the whole amazing truth.

Verloc was the "other man." "Mrs Verloc," he said, "it strikes me that you know more of this bomb affair than even you yourself are aware of." Mrs Verloc sat still, amazed, lost in boundless astonishment.

What was the connection?
And she became so rigid all over that she was not able to turn her head at the clatter of the bell, which caused the private investigator Heat to spin round on his heel.

Mr Verloc had shut the door, and for a moment the two men looked at each other.
Mr Verloc, without looking at his wife, walked up to the Chief Inspector, who was relieved to see him return alone.
"You here!" muttered Mr Verloc heavily.

"Who are you after ?" "No one," said Chief Inspector Heat in a low tone.