A haggard O’Brien, with a scraggly beard, is released from an alien prison. He seems disoriented… “I can’t leave. Where would I go to?”
A concerned Kira watches as smug aliens infodump that they punish offenders by inserting extended memories of incarceration — twenty years, in O’Brien’s case.
Sisko explains to Keiko that O’Brien “apparently got curious about Argrathi technology and asked a few too many questions,” and says Bashir will try to erase those memories.
O’Brien is overwhelmed riding the runabout back through the wormhole. “I’d forgotten how beautiful it was.” He tells Bashir he was alone during his entire incarceration, but we see a flashback in which O’Brien meets Ee’char, who is thrilled to have a cellmate, greeting O’Brien with a friendly “Welcome to hell.”
Bashir tells Keiko he can’t remove the memories because [technobabble], but reminds her that O’Brien has bounced back from suffering before.
O’Brien remembers that Keiko is pregnant, but he’s still disoriented. He’s picking at his food, dividing it into small portions, with the intention of saving it.
In a flashback, Ee’char hides a stash of food and teaches O’Brien how to draw geometric patterns in the sand, and manages to laugh playfully at O’Brien’s efforts.
Worf is spending quality time with O’Brien, playing darts and offering to go kayaking on the holosuite, but O’Brien is distracted because he thinks he sees Ee’char on the Promenade.
Jake patiently helps re-acquaint O’Brien with various tools. Later, O’Brien seems to be making good progress re-establishing his role as chief, and has stopped seeing the counselor Bashir prescribed for his recovery. O’Brien gets crabby at Bashir’s polite professional pressure.
In another flashback, Ee’char happily asks O’Brien to tell him about Keiko again, but O’Brien is testy, and starts ranting. Ee’char has to get physical with him to prevent him from being punished.
In Quark’s, O’Brien is crabby and aggressive, and is surprised when Ee’char shows up, saying, “I’m your friend. You need me.”
Ee’char pops up again later when O’Brien is getting ready for work, but O’Brien brushes him off, and is not at all thrilled when Sisko calls him to his office to scold him for skipping his counsellor sessions. O’Brien tries to bargain, but Sisko cites Bashir’s opinion that O’Brien is not fit for duty.
O’Brien charges out of the office, blows off Dax’s friendly words, and confronts Bashir. “The O’Brien that was your friend died in that cell.”
Ee’char follows O’Brien around the station, urging him to let Bashir help him. O’Brien goes for a long walk, and is still stressed when he comes home, yelling at Molly and preparing to strike her. He’s horrified, and takes out his anger on crates and barrels in a cargo bay.
When Bashir catches up to him, O’Brien has taken out a phaser, and seems ready to end it all. For the first time, he mentions Ee’char.
In another flashback, we see O’Brien and Ee’char are both ragged, starving and despearate. After lights out, Ee’char sneaks to a secret hole. O’Brien wakes up and attacks him, accusing him of hoarding food. By the time O’Brien realizes Ee’char had divided his stash into two portions, evidently to share, it’s too late — O’Brien has killed his friend.
Back in the present, O’Brien is disgusted that, even though it was a simulation, he behaved like an animal. Bashir points out that an animal would not feel such guilt.
O’Brien permits Bashir to take the phaser, and we see a pleased Ee’char bidding Miles farewell and fading away.
Later, Bashir has prescribed an unspecified medication that will prevent the hallucinations, but O’Brien will need to keep working on his memories — and the guilt.
After making a joke about how he’d prefer to meet with a counsellor than talk with Bashir, O’Brien takes a moment to articulate his gratitude, and Bashir responds with, “What are friends for?”
The final scene shows Molly joyfully hugging her father, as a happy O’Brien affirms, “Daddy’s home.”