Thomas is a Visitor and chief engineer of the Visitor fleet. He was appointed Anna's acting second-in-command after Marcus was incapacitated. Marcus has now recovered and resumed as second-in-command. Thomas is said to have designed the V motherships himself.
Made his appearence in ("Concordia"). He is architect who designed Concordia's structure, and is the Chief Engineer. When Marcus was shot by The Fifth Column, he was willing to be Anna's right-hand man, and would assist Anna.
He then questioned how Anna would deal with a child that wasn't hers, she said that all Ryan's daughter knows is that she was in pain and Anna healed her. He also accompined Anna to see the deal with the live aboards and even told Anna of their plan with Concordia. ("Uneasy Lies the Head")