Thames Chabon was a black market dealer who used to have Skulduggery Pleasant's skull. He also had contacts with the British Sanctuary and knew of a secret entrance which he used to smuggle goods in and out.
Whilst trying to get in touch with Chabon, Valkyrie Cain mixed with the wrong crowd and was captured to be used as food for an arena run by the Promoter. Caelan agreed to help her contact Thabon in exchange for his freedom.
Thames had been offered to sell Skulduggery's Skull to Valkyrie. Before he flew out to Ireland, Davina Marr had bought it for triple the price.
After selling Valkyrie a fake skull, she found out that it was a fake. He was chased by her, Tanith Low and Fletcher Renn. When he was caught, he was forced to reveal that he sold the skull to Marr.
About four years after Skulduggery Pleasant was freed from the Faceless Ones' universe, Chabon met with the Remnant-Infected Tanith Low. He gave Tanith a way into the British Sanctuary in return for Sabine. Why he wanted her is unclear, but it may be that Sabine had used her Magiphage abilities to swindle him. Outside the Sanctuary, Tanith betrayed her, and Chabon ordered his men to take her away. After Tanith was captured in the Sanctuary, Moribund revealed that he had watched as Chabon activated the secret entrance so he could free her.
Chabon was a double-dealing man, who would attempt to sell forgeries to more than one party interested in his goods. He also would break deals, for example, when Davina Marr paid triple for the Murder Skull.