Prologue: Barney is on the phone asking when the heavy rain will let up. Wojo is watching the rain out the window and feeling depressed. Yemana reads in the paper that someone claims that the weather is controlled by the Rockefellers so they can bring about a one world government. He also points out that Nelson Rockefeller never has an umbrella because it never rains on him. Chano is upset over working in a sieve while downtown they are in a big glass building with radiant heating. Barney relays that the rain won't let up for another day. Beckman, the maintenance man, comes up and says that he'll have to get on the roof to check out the leaks. He says that when the building ws built it was shoddily constructed. Fish comes in and complains about the subway. Harris follows him and says that the rain washes everything off the streets; Fish says it goes into the subway. Chano takes a call from a nightclub owner saying someone started a fight and the place is busted up. Barney sends Chano and Harris, who is upset because he just got out of the rain. Harris asks Chano if he will be wearing a raincoat, he says he wants to get wet on the outside, not on the inside. Fish tells Barney to remind him to change his pants before he leaves because his wife is turned on by the smell of wet corduroy. Beckman says there is six inches of water on the roof and the buildings on either side are draining onto the roof. The water needs to be pumped off but they won't be able to do it until the rain stops. He gives Barney several other things to use to catch the water and leaves. Barney says, 'Into each life some rain must fall. Fish's phone rings, he says, 'Not necessarily,' then opens up an umbrella to answer it.
Part One: The detectives move their desks away from the leaks. Fish takes a call from a woman who asks if the Hudson River will overflow its banks. Barney asks for coffee and Yemana takes some from the roof. He tells Barney that rainwater is the best kind. Barney points out that it has gone through the moldy roof and he says, 'That filters out the impurities.' Chano and Harris come in with Jackie Ace, a stand-up comic who was doing his act at the nightclub; when the audience didn't like his act, he went into the audience to insult them and a fight broke out. The owner of the club said that he is holding Jackie responsible for the damage. Wojo looks out the window again wants to go home. Nick says he should write a letter but he says no, he wants to save all his news for when he goes home at the holidays. Jackie tells Chano he does bicentennial impressions, but they aren't funny. Nick looks out the window and he gets depressed. Harris complains to him that the coffee tastes like a roof. Jackie calls his agent to bail him out. He tries out some of his act on Fish before Chano puts him in the cage. Barney asks if there is any crime and Fish, jerking his thumb towards the cage, says he just missed it. Beckman comes back and reports that there is now five feet of water on the roof. He says that it can't support that much water. Barney tells Nick to to call emergency services. Wojo can't believe that and Beckman says that water is heavier than it looks. As he leaves, Jackie tells him one of his jokes and he laughs. Barney tells emergency services about the water and they tell him it's structurally impossible for the roof to collapse. Just then the roof groans. Barney says that the man on the phone would stake his reputation on it. Wojo says weakly it's good enough for him. Harris says a little water won't bring the building down. Fish says, 'You'd be amazed how much water an old structure can hold,' and goes to the restroom.
Part Two: The water has seeped through the walls and into the files, rendering them unreadable. A man from emergency services insists the roof will be all right. The roof groans again and Barney says they have been happening every 15 minutes. Jackie jokes that they shouild take it to the hospital. The man says the roof is settling. He says buildings move, breathe, and contract. Jackie's manager, Arthur Bloom comes in to bail him out. The man says to put the files in the cage because the bracing for the ceiling is in there too. Bloom says he may lodge a complaint about the conditions and Fish says he'll sign it. Harris takes his turn looking out of the window. He laments that he's not retired and living off his royalties from being a best-selling author. Gardeno, the owner of the night club, comes in and demands that Jackie pay for the damage to the club. The emergency services man says nothing will happen to the roof. But after he leaves, it creaks again. Chano joins Wojo and Harris at the window and asks to talk to Barney. Bloom asks Gardeno to give Jackie one more chance. When he tries to do a James Monroe joke, Gardeno asks who James Monroe is and Jackie tells him to read a book. Chano is depressed that the harder cops work, the more things stay the same. Chano says it's a waste of time. Barney says they contribute but Chano says they aren't respected. He says he now wants politeness; Barney says he's still aiming too high. Bloom asks Gardeno how Jackie can pay damages if he isn't working. Gardeno says he'll take everything Jackie has; he says his ex-wife has everything. He says he has talent and starts singing. Bloom tells Gardeno that he should book Jackie back again so he can get even. Barney says this is the worst night he's ever spent on the job. Fish tells him, 'Well, you're young yet.' Beckman says they have a pump on the roof and the water is being pumped into the air shafts. Wojo then comes in and says water from the air shafts is leaking into the storeroom. Chano says Gardeno won't press charges and will keep Jackie on until the damages are paid, and no one from the audience has pressed charges, so Jackie is released. He invites everyone to the club where he will do a new act, his Renaissance Revue. Gardeno still doesn't get the jokes, though. Wojo says everything is ruined in the storeroom and the only place in the building without running water is the restroom. Then another creak, and some plaster falls from the ceiling. Barney has Nick call the division commander, then he starts yelling about the situation. He says he's tired about trying to 'keep the lid on this potboiler situation we're living in' and they are going to hear from him. He says he doesn't want to hear any fiscal garbage but Nick can't get through because the phone lines are washed out. Beckman comes in and asks what happened. Harris tells him about the ceiling and Beckman, thinking it happened after Barney yelled, says that you can't yell at an old building.
Epilogue: As everyone cleans up, Barney apologizes, saying that he's always the one why says to put things in perspective. Harris says eveveryone was depressed and Fish adds he was the first person to put it into screams. Chano says depression is like a cold: one guy gets it and starts passing it around. Nick quotes his grandfather: 'Many things look bleak at the moment of occurrence, but at least we ain't got locusts.'