In 2154, nine crew members were abducted from Enterprise NX-01 and taken to Verex III to be auctioned off. Captain Archer was able to gain access to the processing station by using an old authorization code provided by Arik Soong, and discovered a way to disable the neurolytic restraints with which all of the slaves had been outfitted. With Soong's help, Archer disabled all of the restraints, causing a mass escape attempt. In the confusion, Archer was successfully able to rescue his people and escape. (ENT: "Borderland")
In the final draft script of "Borderland", Verex III was described as "a barren-looking world. In the shadows of a large crater, we see the lights of a settlement – the slave market." The script also referred to the planet as "a busy place" and described the slave market as "dark, smoky and alive with flitting shadows... the market is broken into fenced-off holding pens with slaves awaiting processing. The entire operation has a ratty, fly-by-night feel... as if it's forced to move around a lot."
Concerning Verex III, Manny Coto once commented, "The idea of a slave world and slave auctions I found just wonderfully fascinating." ("Before Her Time: Decommissioning Enterprise, Part Two: Memorable Voyages", ENT Season 4 Blu-ray special features)
According to Stellar Cartography: The Starfleet Reference Library ("Federation Historical Highlights, 2161-2385"), the Verex system was located in the Beta Quadrant. The system's primary was a M-class star. In the late 24th century, it was an independent system.