If Rescue Me had a 5th season and I wrote episodes for it, I would have a character that pretends to be Irish. He keeps his head completely shaved and avoids the sun.
An African American, a second character, observes the cook off between friendly Irish and Italian firefighters.
A third character, is a closeted homosexual. In an act of brotherhood, Dennis Leary's character takes him under his wing. Since the gay character doesn't go to illicit massage parlors or strip clubs with the boys- he gets sent to the medical office for refusing to be "one of the guys".
Dennis Leary's character coaches him- "Tell them you have dreams of just women. You need to rehearse this. You only dream of the babes". In the mean time, he kicks himself for coming along with him when he exhibits a penchant for gambling at Atlantic City, Vegas, and scratch off lottery outlets.
The African American goes to a bachelor party and he and his college buddies take the groom to a drag queen show (music playing is Anita ward's "Ring My Bell") during the night as a joke. The joke is cool until he spots one of the drag queens as the closeted gay guy from his firehouse.
Leary's character catches wind of the situation and takes them all fishing as a male bonding outing. They catch nothing. They decide to pick up sea bass at a roadside stand on the way home.
Someone filling in at the firehouse suggest beer batter for the fish. Flouting the no alcohol ban, they have a fish fry. The bass was excellent and they have a fine meal. Thirty minutes after the meal, they all get extremely sick, starting with the officer. The bass turns out to be New York harbor poisoned sea bass.
Everyone has to go on sick call. The whole house has difficulty breathing, swollen faces and nausea. The whole house is put on quarantine and replacement units are quartered blocks away. The police counter terrorism team responds in moon suits and check for anything suspicious.
The officer who gets sick, gets a ribbing from the command, when they miss a third alarm fire during their illness. The rival fire house makes prank calls pretending to be the insurance agent and inquires if they need a policy that covered ambulance service. It does not go over very well.
TV footage shows the firehouse members taken away in ambulances. Everyone is discharged within 2 days except the guy who pretends to be Irish. His hair grows out and turns out to be a freckled red haired Dominican.
Dennis Leary's character, fooled by the imposter's Irish brogue, does his ball exercise routine pondering what it means to be Irish. Working on his core group, he reminisces about his lost buddies. The music playing in the background is Van Morrison's "Sweet Thing".
He is exhausted and rolls the core ball back to its spot in the gym. He discovers the remaining bottles of beer that weren't used for the beer batter. He puts it in a garbage can and takes it outside.
He sees the African American character come in for work, an hour and half early, like everyone in the firehouse. He says hello, and says to him "I think the cool thing about working in the fire department is the unity in good acts".
The tone goes off and they both drop what they are doing and gear up. It's for a transportation fire, fuel truck vs. a 99 cent store. When they arrive at the scene, guys are laying down foam and news choppers are whizzing by.
The officer and the guys get off the rig, "Let's get to work", the officer says, and the music cues to the Blues Traveler "Conquer Me".