While walking London's backstreets one evening, Arthur Bryant sees a middle-aged lady, slightly the worse for wear, coming out of a pub. The next morning, her lifeless body is found at the point where their paths crossed. In itself disturbing enough, but there's a twist: the pub has vanished. Bryant is convinced that he saw the street as it had been a century earlier; however, having recently lost an urn containing the cremated remains of an old friend, could the elderly detective be losing his mind as well? It soon becomes clear that the lives of a number of women have been cut short in London pubs. A silent, secret killer is at work, striking in full view, and yet nobody has a clue how, why, or where he'll strike next. The main suspect seems to be a recently released mental patient. But knowing who the killer is and catching him are two different things. As their new Peculiar Crimes Unit team goes in search of a madman, detectives Bryant and May find themselves on the pub crawl of a lifetime - and come face to face with their own mortality.