Vark had previously served in the Klingon Defense Force during the Dominion War. In 2379, in the month leading up to the attempted takeover of the embassy, fifteen new employees were hired by Vark for the kitchen staff, all members of Klahb, the group that attempted the takeover.
After they realized that Worf and one security guard had escaped, Vark and Rov, the leader of the invaders, began to argue about their plan. Vark had wanted to wait until Worf had left the embassy to attempt the takeover. Later, when Alexander Rozhenko began to convince some of their captors that Rov planned on letting them die as martyrs but escaping himself, several of them, including Vark, began to get angry with Rov. After Vark discovered that Rov had refused to serve in the Klingon Defense Force during the Dominion War because he was not given the position of an officer, he became frustrated enough to attempt to kill Rov, but Rov was too fast and shot him first with his disruptor, killing him. (ST - A Time to... novel: A Time for War, A Time for Peace)