Za'dag was a soldier in the Breen Confederacy during the Dominion War and was an instrumental participant in the Breen attack on Earth in 2375. He beamed to DP-7, the weapons platform responsible for the defense of North America, from a transporter station on Earth, killing a transporter operator in the process. He then took control of the platform and used it to fire on the USS Enterprise-E and the USS Columbia later in the battle. Then Jean-Luc Picard beamed aboard the platform and stunned Za'dag, then shut down the platform. (TNG short story: "Eleven Hours Out")