The USS Defiant (NX-74205) is a fictional starship in the television series Star Trek: Deep Space Nine (DS9) and the feature film Star Trek: First Contact. The lead ship of her class and one of the Federation's first purpose-built warships, the Defiant first appears in the third-season DS9 episode "The Search, Part I", after which it plays a significant role throughout the series in the ensuing Dominion War. While the original Defiant is destroyed in the seventh season episode "The Changing Face of Evil", Starfleet sends a replacement ship of the same class, the USS Sao Paulo in the episode "The Dogs of War", which receives special dispensation from the Chief of Starfleet Operations to be renamed as the Defiant.