The passage was lighted with electricity, but she did not observe anyone about, nor did she hear a sound.

She showed out Mr.
Clancy and then returned to the kitchen.

Certainly the assassin may have been concealed in the bedroom and have stolen into the sitting-room when Susan Grant was showing out Mr.Clancy.

Perhaps then he killed the deceased suddenly, as we said before.

He could have then come up the stairs and have escaped while the servants were at supper.
It might have been the murderer who opened the door, and was overheard by Thomas.
"The policeman was on duty about ten, as he was seen by Susan Grant when she showed Mr.Clancy to the door.