Barlow and Watt, as TV detectives of today, sift evidence from yesterday - dramatised from contemporary documents and newspapers and newly discovered material.
Victims three and four are found - and Barlow seeks suspects.
The fifth victim - and the writing is on the wall for Watt's theory. Can Barlow do better?
The Ripper's work is done - but, in. November 1888, the panic and repercussions have only begun.
The investigators tot up the evidence against some of the men suspected of the Ripper murders - from a Polish immigrant to ' the highest in the land ...'
The trail leads from damp East End alleys to the haunts of the rich and privileged.