Emergency plan ZZA was an emergency procedure used aboard the USS Enterprise-D. The plan activated automatic defense procedures aboard the starship. In 2367, following the incapacitation of the humanoid members of the Enterprise crew by the Paxans, Lieutenant Commander Data ordered the activation of the plan in order to help fend off the Paxan attack. (TNG: "Clues" ) The plan is referred to in the script as "Zed-Zed-Alpha".