"The IX serum has been eating at you since you injected it."
―Watcher X[src]

The IX serum, also known as Serum IX, was a drug used in Castellan mind conditioning. The serum was distilled from the chemical dimalium-6 found on Quesh and specifically formulated for its subject. It took the serum anywhere from three to thirty days to circulate through the subject, altering their brain chemistry to make them more susceptible; after the serum was fully absorbed, the subject was imprinted with a code word that opened the affected mind and forced them to obey the subsequent commands. If the IX serum is reintroduced to the subject, it is possible to reset the conditioning, at the cost of carving neural pathways and getting bleach on the brain, even risking the subject being sent into a permanent vegetative state.