Dr. Sinclair (played by Malcolm Stewart) was a minor character from the Smallville episode "Onyx". He was a LuthorCorp scientist working with Lex Luthor on an experiment to create kryptonite-irradiated crops that could grow in any environment. Lex and Sinclair proceeded with the experiment, but the kryptonite exceeded its target temperature. As the device containing the kryptonite began to overload, Lex shoved Dr. Sinclair aside just as a burst of energy was released from the kryptonite, which had turned from green to black. Caught in the blast, Lex is split into two seperate beings before falling to the floor. A short while later, he gets up and escorts the wounded Dr. Sinclair to the hospital, unaware that another Lex is watching him.
Death[]
Alexander discreetly follows Lex and Sinclair to Smallville Medical Center. While Lex is busy speaking with Clark Kent and Chloe Sullivan, he sneaks into Sinclair's room and asks him about the accident. Sinclair asked if Lex could retrieve his notes from the lab so they could figure out what happened, but Alexander then murdered Sinclair by putting air into his IV tube, causing an air aneurysm.