A Romance by Fergus Hume.
In four hours Major Measurby awoke from his unnatural slumber, with an aching head and a feeling of giddiness. For some moments he could not collect his thoughts sufficiently to remember where he was. No one had come into the room during his sleep, and all was as he had seen it, saving that outside the brilliance of day had faded into a delicate twilight. He looked at the empty couch, at the glasses on the table, and then sprang up with a loud cry.
He had discovered the loss of the ring.