Did it really all happen? Was it just a dream the Time Traveller had in his workshop?
 
The friend known as the editor believes it was all just a good story. Our narrator returns the following day to the workshop to investigate further and is told insistently that indeed, he really does travel through time. He is told, "I’ll prove you this time travelling up to the hilt, specimens and all."

The narrator hears noises from the workshop and enters to find the time machine, along with our Time Traveller, has vanished. He waits through lunch, and then realises he may never have the real answer, since three years has elapsed since that episode and the Time Traveller has not returned.