Kalbez was the ambassador of the Warpwrights of Phaidon on Gallifrey. He and Plutus orchestrated a plot to plant a computer virus on the Moros, framing the Time Lords to escalate tensions with the Monan Host; to assassinate the President of Phaidon and become his acting successor; and to blame a terrorist attack on Gallifrey on the Monan Host. The goal was to form an alliance between the Warpwrights and the Time Lords and to begin a war with the Monan Host. However, he was caught when Romana II and Leela recognised Gaal as the perpetrator of the terrorist attack; upon being confronted during a meeting with President Livia, Kalbez confessed his involvement in the scheme and, with Gaal, attempted to frame Leela and Ace as traitors to Gallifrey. However, he was trapped by Irving Braxiatel and exiled or executed by the new President of Phaidon.
After Romana II and Leela changed the timeline so that the Moros was never destroyed, Narvin arrested Kalbez and Plutus, averting the plot. (AUDIO: Enemy Lines)