David McGowan

chloride of cobalt for sending invisible messages

Then, virtually overnight, he changed his name and appearance, left the country, and broke many of his connections. Years later, his only brother wouldn’t even be able to find him.”

The Man From Beyond and Haldane of the Secret Service

Sir Arthur Conan Doyle, creator of fictional detective Sherlock Holmes and possible perpetrator of the infamous Piltdown Hoax of 1912