Nalbis was a member of the Triannon species and a member of a religious zealot sect led by Pri'Nam D'Jamat.
He aided D'Jamat in hijacking Enterprise NX-01 in order for his religious faction to use the ship in a war aginst a rival religious faction.
Nalbis was ordered by D'Jamat to guard Commander Trip Tucker in engineering to prevent the chief engineer from manipulating the warp engine. When D'Jamat went to engineering, Nalbis confirmed that Tucker was not guilty as he had been watching him the whole time. He informed D'Jamat that something was wrong with the EPS manifolds on "D" deck, section J15.
When Nalbis and Yarrick were sent to "D" deck, Nalbis was shot in the back by Captain Jonathan Archer. (ENT: "Chosen Realm")
Nalbis was played by actor David Youse.
In the final draft script of "Chosen Realm", Nalbis was identified as the Triannons' engineer. The first scene that featured him in that script was ultimately cut. In it, he listened to Tucker talk to him and Yarrick about Enterprise's warp engine, then ascertained from Tucker that the antimatter stream flowed through a particular conduit, which Tucker identified as the primary plasma duct.