A merchant chemist in the Delphic Expanse who sells Archer the formula for synthesising trellium-D, bargaining for exotic spices from Enterprise's galley.
B'Rat Ud appears in Rajiin. Archer, Tucker and Reed seek him out in a crowded trading bazaar because Tucker's attempts to produce trellium-D, the substance that insulates ships against the Expanse's anomalies, have nearly wrecked engineering.
The chemist knows how to make a stable form of the compound and is willing to part with the method, but he has little interest in ordinary currency. What catches his attention is the offer of seasonings he has never encountered, and the deal is closed with a selection from Chef's stores, black pepper among them.
While the officers are on the station Archer is approached by the slave Rajiin, whose rescue turns out to be a trap set by the Xindi.