Stef interrupts Steve's extremely close haircut to tell him that his buddy, Wayne, called saying he wants to sell a knife that could've belonged to Jack the Ripper. When they meet later on, Wayne tells the oral history - no paperwork is available on the killer that was never caught - of the Martin family, a patriarch of which was a trash collector in Victorian England named David. He found the knife in a gutter in Whitechapel, Jack's haunt, and his family used it in their kitchen from that day forward. Wayne bought it for $4000 to inspire him as he wrote his book, but now the knife gives him bad vibes, and he's ready to be rid of it.
On the other side of town, Steve's collector friend, Vince, shows Steve a chastity belt that he's willing to sell. At $1250, Steve snaps up what he thinks is a bargain, but when he meets with an expert in the field of medieval torture devices, he learns that these belts were almost all mass-produced in the 1800s in England - the notion of a chastity belt was impractical, since a lover could find a locksmith to undo the belt as easily as a jealous husband could find one to make it. They were only a satirical jest and not an actual, extant tool - in fact, medieval museums have removed them from their collections.
Stef wasn't able to find any documentation linking the knife to David Martin, so Steve goes to a specialist who confirms that the knife is from Victorian England, but says the length of the knife indicates it probably wasn't Jack's. Undeterred, Steve brings the knife to a Ripperologist named Christopher T. George, who says that the knife absolutely could've achieved the throat slitting and gut spilling for which the Ripper was famed. His next stop has to be to his friend, Tamarra, who will use psychometry to detect psychic clues left on the knife.
Without knowing Steve's suspicions about the knife's history, Tamarra detects two layers, one of normalcy and warmth, and another of fear, anger, and death. Steve asks if there is just one death on the knife. Tamarra says there are many, and that the killer was never caught.
The information from Tamarra and the Ripperologist convince Steve that he wants the knife to be part of his personal collection. Since no museum would exhibit such a piece without some kind of paperwork showing the provenance, he won't be able to recoup his investment, and so he can't pay Wayne the $4,000 he invested in it. Wayne says that he is happy to have the knife out of his life - it served its purpose in inspiring him to write his book, and now it has become too dark. He gives the knife to his old friend free of charge.
Steve gets a close call on one of his death defying escapes.
Steve takes the axe to get it tested for authenticity.