A brass pocket watch disappeared from the locked office of a wealthy mill owner.

Nothing else was stolen.

The watch had belonged to his father.

Cryer questioned every employee.

All denied seeing it.

The office had remained locked throughout the night.

The key was kept in the owner's bedroom.

Cryer examined the desk and noticed a faint circle of dust where the watch had rested.

Beside it was a second, smaller circle.

Something had been placed there recently.

A glass.

Cryer searched the office again.

Behind the fireplace he discovered a narrow opening in the brickwork.

Inside was a folded scrap of paper.

It contained a time:

"2:40."

The following night Cryer waited inside the office.

At precisely 2:40, nothing happened.

At 2:41, the watch appeared on the desk.

Nobody had entered.

Cryer had not left the room.

The window remained locked.

The owner demanded an explanation.

Cryer could give none.

He kept the watch as evidence for several weeks.

During that time, it stopped repeatedly at 2:40.

He eventually returned it.

It disappeared again three months later.