Spending time with three of Britain’s most notorious serial killers at the atmospheric Old Police Cells Museum makes for an unnerving if not fascinating proposition.

Ian Brady, Dennis Nilsen and Peter Sutcliffe respond to letters from members of the public. Glenn Chandler (creator of Taggart) has drawn directly from these real-life letters and created a play that is even more disturbing than expected.

Initially, the men seemed innocuous enough – a sense of justice having been meted to them feels satisfying. As things progress, more psychological, emotional and moral questions are proffered, their “normal”, humorous chat rudely punctuated with disdain, indignation and superiority.

The actors – morphing into the infamous prisoners – keep you entranced and are at times extremely intimidating.

Who are the people that write to felons such as these, enabling them to have a voice, feeding their egotism and sanctimoniousness?

Brady states in one letter that people took bricks from his demolished house – maybe this voyeuristic fascination with horror is innate in all of us?

Killers is a play to see more than once as there are so many nuances that can be missed. Fascinating stuff that leaves more questions than answers.