Knapp and Naros lead the Antietam on a surveillance mission that gets out of control, while Zen and Aster's relationship is threatened by someone from the Trill's past.

Captain Shelby experiences a personal loss, while the rest of Excelsior’s crew uncovers some of the secrets of the Grey. Naros history with Tren'La make working with Princess Illiana difficult, as they discover more clues that link the Grey with the tetrahedrons.

While the Excelsior is trying to lend assistance to a world that is a long-time member of the Federation, Security Chief Matt McCabe finds himself developing suspicions that do not endear him to the world’s ruling government. He grows close to a local security officer he encounters, while they investigate the supposed terrorist activities that the planet is suffering from, but they soon stumble into something far more dangerous.

The Federation is considering using Centris III as a listening post. It is believed to be uninhabited and offers a perfect chance for some well deserved shore leave. "The Camping Trip Mission" begins and Barrett, Ro and Aster get more than they bargained for. The camping trip becomes a life and death battle for one of the team.

While exploring the currents in the Briar Patch, the Excelsior crew realize the Tholians have a greater presence in the patch than previously thought. An ambush on a planet surface leaves Barrett racked with guilt and it's up to his friends and colleagues to rally round him. Meanwhile, a diplomatic conference with the Tholian Ambassador raises more questons than answers.