Its plot speculates what might have happened if H. G. Wells had built a real time machine to travel to the 1970s in search of Jack the Ripper.

The novel was adapted to film the same year, under the same title, by Alexander's friend Nicholas Meyer who had optioned the story after reading the early pages.

In the next chapter, Wells is introduced showing off his brand new time machine to a group of men, including Stevenson.

As Stevenson murders several women, Wells pursues him while hampered by a love affair with Robbins, to whom he does not dare tell the truth.

[3] After the release of Felix J. Palma's 2008 Spanish-language novel The Map of Time, which also has a time-travel plot involving Wells and Jack the Ripper, critics commented on the similarities (and differences) between the two books.