With his head resting upon his hand, he seemed to be engaged in tracing patterns upon the tablecloth.
"Wrayson knows nothing of Barnes beyond the fact that they are neighbours in the same flats.

Being the assistant editor of a journal of world-wide fame, however, he has naturally a telephone in his flat.

By means of that instrument he receives a message in the middle of the night from an unknown person in an unknown place, which he is begged to convey to Barnes.

The message is in itself mysterious.

Taken in conjunction with what happened to Barnes, it is deeply interesting.