Lansor (portrayed by Vaughn Armstrong) is an alien who appears in the Star Trek: Voyager episode "Survival Instinct". A former Borg drone, he was once part of Seven of Nine's former unimatrix and operated under the designation Two of Nine, Primary Adjunct of Unimatrix Zero-One.
In the year 2368, Two of Nine was one of four survivors of a Borg sphere that crashed on an uninhabited planet in the Delta Quadrant. The destruction of their vessel severed the drones' link to the Borg Collective and while they tried to survive in the jungle as they waited for rescue, they began to recall their individual memories from before their assimilation. Two of Nine, formerly known as Lansor, remembered working as a mathematician back on his homeworld. He also recalled the violent circumstances of his assimilation and was disgusted by how the Borg had mutilated his body, including amputating his hand and replacing it with a servo-armature.
Before the drones were recovered by the Borg, they attempted to hide and destroyed their distress beacon. However Seven of Nine, terrified of her new-found aloneness, hunted each of them down and forcibly interfaced with each of them using her assimilation tubules. She caused the left parietal lobes of their brains to be transformed into interlink nodes that linked them together in an ad hoc collective, then erased the act from their memories. She then led them back to the crash site, where the Borg retrieved them.
Eventually, P'Chan, Lansor and Wilkarah escaped the Collective, but could not break their ad-hoc link, and thus were denied true individuality. In 2376, they sought out Seven of Nine on Voyager in the hopes that she could help them, and discovered her responsibility for the link.
The Doctor, Voyager's holographic chief medical officer, found that the only way to break the link was to remove the interlink nodes. However, this would kill them within a month. Seven and the Doctor decided to perform the procedure, knowing that they would prefer a short life as individuals to being linked together. Lansor decided to spend his remaining time at the Markonian outpost at which Voyager had been docked.