Stardate 51825.4: Aboard the Runabout Shenandoah, Nog and Jake head to Ferenginar to deliver a diplomatic message to the Grand Nagus. Leaving from Starbase 257, they are attacked by a Jem'Hadar fleet on their way to the base. While the rest move on, one Jem'Hadar ship continues to attack the Shenandoah. Fortunately for the Nog and Jake, they are backed up by a sister ship of the Defiant, the Valiant, which is staffed by members of Starfleet Academy's Red Squadron.

When Voyager finds a planet with much needed deuterium, the bad news is the planet is classified as a "Demon Planet" due to its toxic and deadly atmosphere. After failing in their attempt to beam up the deuterium, Paris and Kim volunteer to go down to the planet and mine the material themselves.

However, both their environmental suits fail, leaving them near death, as Voyager hurries to rescue them. When they locate the two, both are alive and well, existing on the planet without their suits on! When they are brought back onboard, they quickly find the ships atmosphere is killing them. Paris and Kim find they can only survive in the planet's atmosphere, something Voyager can't provide all the way back to Earth. But is there a different reason the two can only survive under the planet's atmosphere? The answer shocks the crew.

Sally turns to romance novels for inspiration when it's time for her first kiss with Officer Don. Unfortunately, whether they try it on a windy, moonlit bluff or in the Solomons' kitchen, the kiss just isn't special enough. Sally becomes resigned to breaking up with Don, but when she goes to the police stable to tell him, the magical combination of horses, thunder, lightning, and Don's newfound forcefulness combine to make Sally realize Don's the guy for her after all. Dick is perturbed because Lucy the cafeteria lady charges him - and only him - for crackers. Realizing he has no control over her inexplicable dislike for him allows him to free himself from being bothered by her unjust treatment. Harry graduates from night school, and he and fellow classmates Mrs. DeGuzman and Larry reminisce about all the great times they had together during their ten-week enrollment.

Kelly finds it impossible to trust Brandon as he works late every night for several weeks. Brandon assures Kelly that he will never leave her and suddenly asks her to marry him. They experience doubts, but decide that they are ready for a lifetime commitment. Noah entertains Gwyneth, a longtime friend. She secretly has a crush on him, and kisses him on a ferris wheel. Noah insists that he is not interested in her. David becomes extremely jumpy after being robbed at an ATM. He gets drunk, steals a gun from the After Dark's cash register, and staggers into the alley behind the club. When Noah and Gwyneth try to stop him, he shoots at a dumpster; a bullet richochets and hits Gwyneth in the arm. Donna asks Gwyneth to stay at her apartment because she doesn't trust her around Noah. Valerie learns that she is a match for a leukemia patient in need of a bone marrow transplant. The man's son urges her not to go through with the operation, as his father molested both of his daughters and may do

A female magician performs at City Hall and Mike asks her out. Stuart and Carter purchase a bar. After sleeping together and telling him she's not interested in a long-term relationship, the magician says "I love you" to Mike. Stuart wants to make the bar a gay bar. Mike has trouble breaking up with his girlfriend. The bar is closed because it was missing a permit, leaving Stuart and Carter penniless. Mike finally tells his girlfriend how he feels and they break up.

Stuart lobbies to become Carter's roommate. After Carter's apartment is robbed, he must let Stuart stay. A rat on the loose in City Hall wreaks havoc on the staff and Paul's cat.

The case of a teacher's shooting uncovers a vendetta involving the rape of a mentally challenged coed by three students, whose attorney claims they weren't aware of her condition. Briscoe is devastated to learn of his daughter Cathy's death.

When a body is found between the blades of a harvesting machine, Sam is called to the scene to examine the body.

At first it looks like an accident, but when the body is re-examined later, a wound is discovered that was not made by the harvester. As Sam delves deeper, she discovers that the case could have something to do with someone's past in Northern Ireland.