Will learns that 19th Century history is a lie: Charles Babbage's difference engine was a huge success, providing the growing British Empire with robots, digital watches, airships, and even the first rocket to the Moon.

After returning to London, Will and Hugo take on a case for Sherlock Holmes – to discover the identity of Jack the Ripper to learn more about the witches' cabal.

Will and Tim return to the past, meeting an invisible H. G. Wells, the Elephant Man, the Brentford Snail Boy, and another Will from an alternate future.

After finding Hugo's true residence in the Buttes Estate, Will and Tim set out to save the 19th Century and the future from the influence of the Witches of Chiswick.

"Anti-Will" faces Hugo, travels back in time to prevent the Babbage Difference Engine from being recognized, then returns to the circus to finish his goal of controlling the world.