After being scanned by an unknown alien spaceship, the
Enterprise crew discover that their personal memories and the personnel files in the ship's computer have been partially erased. They do not remember each other or their own identities. Unbeknownst to the crew, a mysterious new member has joined the bridge. The bridge crew recover the personnel files in the ship's computer and re-learn their own names and positions aboard the
Enterprise. With no knowledge of their prior contentious relationship, Commander Riker and Ensign Ro Laren are immediately attracted to each other and engage in a brief sexual relationship. The computer claims the Federation is engaged in a protracted war with an alien race called the Lysians, and the
Enterprises mission is to destroy the Lysian central command while maintaining communications silence. The manifest identifies the new member as Commander Kieran MacDuff, first officer of the
Enterprise. MacDuff volunteers for Doctor Crusher's attempt to restore the memories of the crew, but apparently reacts poorly to the treatment and discourages further attempts. The
Enterprise encounters and easily destroys a Lysian ship, and closes in on the Lysian central command without difficulty. Noting the Lysians' extremely limited defenses and firepower, Picard expresses suspicion about the alleged state of warfare and questions the order to destroy the central command. MacDuff insists on carrying out the attack and attempts to take control of the
Enterprise, but is subdued by Worf and Riker. MacDuff is identified as a Satarran, an alien race at war with the Lysians who attempted to use the
Enterprise against the Lysians. Picard apologizes to the Lysians for their attack, and Dr. Crusher is able to restore memories to the crew. In Ten Forward, Ro and Counselor Troi both gently tease Riker over his tryst with Ro. ==Reception==