Morgan Andrew Robertson (1861-1915) was a popular American author of short stories and novels and claimed to be the inventor of the periscope.
'Over the Border' is a fascinating tale about hypnosis and mesmerism. The narrator lost much of his memory for many years after leaving his former life as a sailor. One night he visits a theatre where a hypnotist is performing. On his way home on the tram, he hears two doctors discussing a case at the hospital - a man with amnesia. One doctor recommends hypnosis as therapy to try to access the lost memories.
The narrator is inspired to track down the hypnotist from the theatre and see whether he can help him recover his lost past...but the results of the mesmerism are quite beyond anybody's expectations.