Tom Holland

And that was Sherlock Holmes.

And the title of that book derives from the notion of a scarlet thread of murder.

So running through the colourless skein of life and our duty is to unravel it and isolate it and expose every inch of it.

And I think in saying that, Holmes is speaking for the times because he is articulating a sense that crime has become susceptible to solutions

that were simply undreamed of by earlier ages.

And it's really telling that part of the glamour of Sherlock Holmes, the reason that contemporary readers take him seriously as the genius that Conan Doyle is presenting him as, is because he is an enthusiast for scientific methods that are ahead of police procedure.

So fingerprints has an ambivalent relationship to that, but he's interested in it.

He analyzes bloodstains.

He famously writes a monograph on the 150 types of tobacco ash.

He's interested in ballistics.

And I think that it's an absolutely enduring fantasy of fiction and films that Sherlock Holmes would have solved the Jack the Ripper case

Well, as Holmes would put it, when you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.

And that is his most famous maxim, which appears in The Sign of Four, which was published in 1890, so the year after the murder of Mary Jane Kelly.

And by that time, it's starting to seem...

Jack the Ripper may have pulled off one final compounding stunt by vanishing into thin air.

Yeah, so in the summer of 1889, a 40-year-old woman called Alice McKenzie is found in spittle fields with her throat cut and slashes to her abdomen.

And although Dr. Phillips says, no, this isn't the Ripper, Dr. Bond, who gave the description of Mary Jane Kelly's mutilations that I read out, he thinks, yeah, it might be.

Yeah, and then there's February 1891, there's one final ripper scare when a young woman called Frances Coles is found with her throat cut, although there are no mutilations to her body at all.

And so I think...

The overwhelming balance of experts today, as it was at the time, is that neither Alice McKenzie nor Francis Coles were victims of Jack the Ripper, which means that the murder of Mary Jane Kelly was the kind of climactic horror, and then he vanishes.