Search - Jack Knife

Whitechapel, London, 1888.
For Inspector Jonas Robb, each night brings new terror. But this night is different. It's brought two strangers-David and Sara-who have arrived in London seemingly with no past. What they do have is incredible knowledge about the Whitechapel fiend known as Jack the Ripper. Because David and Sara do have a past. It just happens to be in the future.
Sent back in time, they're in pursuit of a 21st-century madman whose purpose is to change history.
Already, they can see his sinister influence at work. As the body count rises, Sara and David realize that their quarry and Robb's have become linked in a way that threatens not only Victorian London, but the very fabric of time. Joining forces, they must stop the carnage before it's too late---for the past and future.

Interesting take on Jack The Ripper. Two people travel back in time to the period of The Ripper, chaising another individual who they must bring back to the present.