Jeff Scott runs up the stairs. He kicks open the door to the roof and stops, briefly, before jumping off the edge of the building. He pulls open the parachute and starts to glide down to the ground, but something is wrong. His parachute fails, and he falls to the street. Flack, Mac, and Danny arrive to find the street littered with dead pigeons and one dead parachutist – whose injuries are consistent with a jump gone bad. Flack tells them that Jeff Scott was the best in the business, that he was hired to do this jump and specifically today because the conditions were perfect. Danny mentions that the forecast has changed to "slightly cloudy with a chance of birds".
Danny wonders what could have caused all the birds to drop out of the sky – electrical storm? Bird flu? Nope – it's poison, according to Flack. Mac realizes that the pigeons are tagged – they're racing pigeons, and they're covered with blood. One of them has high velocity spatter on it, which means that somewhere out there, they have another body.
Somehow, Mac manages to lift a print from one of the pigeons, which he gives to Danny to run through AFIS. They talk to Jo O'Keefe, the woman from animal control, to try and figure out why someone would want to steal the birds. She tells them that to someone in the racing community, they could be worth a lot of money. And here Flack always thought they were just rats with wings. The serial number on the tags will tell them who owns the birds. Flack is off to do that.
Meanwhile, across town, a sweet sixteen party has gone horribly wrong. Lindsay, Hawkes, and Stella investigate the death of Edward Archerson, who was found in the front seat of his daughter's sweet sixteen present – her brand new car. After all, "nothing says happy birthday like a $60,000 car," says Lindsay. She mentions that when she turned sixteen, she got her mother's used Pinto.
They examine the car. As Lindsay and Hawkes are moving the body, a cobra comes out of the back seat and bites Lindsay's wrist. They chase the snake only to find out that it belongs to the snake charmer who was performing at the party. Hawkes hastily bandages Lindsay's wound while Stella tries to call for help. They can't get a medevac in, but the EMS will take her to a chopper that will airlift her to the snakebite center.
The pigeons belong to Ray Seeley, as Mac and Danny discover. Seeley's super leads them up to the roof, where he keeps the pigeons. Danny talks to him while Mac is on the phone, getting an update on Lindsay's condition. When Danny asks how she's doing, Mac tells him that she was treated with anti-venom bolus and that she'll be fine. As they reach the roof, they find Ray Seeley dead in his pigeon coop – one of his pigeons perched on top of him.
Danny finds arterial spray on the walls of the coop, which probably explains the bloody handprint they found on one of the birds. Mac goes to talk to the super and learns that Seeley was planning on retiring. The super also mentions that there was a kid that hung out with Seeley a lot – cleaning the coop, feeding the birds – but he never found out his name.
Sid autopsies Ray Seeley. He boils one of the bones and sends pictures to Mac and Danny, who determine that the murder weapon was some kind of power saw, which would explain the high velocity spatter. Mac also tells Danny that they found mother of pearl in the pigeon coop. Flack arrives and informs them that Ray Seeley wasn't really Ray Seeley – his name was Rudy Santangelo, and he was in the Witness Protection Program. Mac meets with Agent Candace Broadbent, who gives him information on Rudy aka Ray, but only as much as she's allowed to tell. Seeley saw two members of the IRA kill a cop friend of his – and the cop's dog – and testified against them in court.
Hawkes looks at the disassembled car back at the lab. It's pristine, except for the scratches on the hood. He then goes to examine the snake that bit Lindsay – which is now unconscious. He finds evidence on the snake that connects it to Chaz Archerson, which is how it ended up in the car. Stella interrogates the boy, who insists that all he wanted to do was scare his sister, not kill his father. Mrs. Archerson says that the snake charmer assured them it was safe, and he came highly recommended. But Stella says that his little joke put Lindsay in the hospital and his father in the morgue, and he's looking at reckless endangerment – possibly manslaughter.
But wait! Sid tells Hawkes that although Archerson was bitten by the snake, it wasn't his cause of death. He was strangled to death, by something with a soft surface, which is why there was no evidence on the skin.
Danny finds Mac to tell him that the pigeon feed in Ray Seeley's coop had been contaminated with termite killer. He tracked down the distributor – all the other bags were clean – and learned that Seeley sent a Jesse Quinn to pick up the feed every week. He goes on to say that Jesse works at a pool table repair shop in Brooklyn. And, Mac realizes, pool tables have mother of pearl inlays.
Hawkes gives Stella the autopsy report on Edward Archerson. She remarks how odd it is that his blood alcohol level was zero, considering they found an open, empty whiskey bottle in his pocket. Hawkes tells her something else odd – a stray hair he found on the victim was obviously ripped out during a struggle, but it looks cut. It's also a 'virgin' hair – not treated with any product. He deduces that it was ripped from a very expensive hair extension.
Flack and Mac visit Jesse Quinn at his stepfather's repair shop. His stepfather tells the detectives that Jesse has been helping Seeley ever since his mother died. Mac asks Jesse when he first got interested in pigeons, but Jesse is unresponsive until his stepfather tells him to come over. He tells Mac that a pigeon flew into his room when he was a kid and wasn't scared at all. Flack asks when he last saw Seeley, but Jesse doesn't answer. Mac mentions that the super told him they had an argument – was he angry because Seeley was selling off his flock? Mac asks if he damaged the coop, because there was a cut on one of the posts.
Jesse's stepfather halts the questioning, but Mac asks Jesse if they could talk alone for a bit. Jesse takes off. Mac and Flack both chase after him. Mac catches up to him as he's climbing a fence and notices bruises on his side. He asks Jesse who did that to him, but Jesse doesn't answer, and soon Flack is on his way. Mac lets Jesse go. Flack is livid. Mac tells him that the kid will be around; it's not like he has a summer house in the Hamptons.
Flack and Mac start arguing about Detective Truby – the cop Mac had arrested, based on information from Flack's memo book, because he was a killer and stole cocaine from a bust. Mac knows that Flack is getting grief from the other cops for not having Truby's back. Mac tells Flack that if he wants to be angry at someone, he should be angry at Truby. As they're leaving, Mac notices dried blood on a wooden crate. Flack tells him that if the blood matches Ray Seeley, Mac's instincts just let their murderer go.
Stella prints the whiskey bottle, but it's not Archerson's, and there is no match in AFIS. She decides to run the print through the Brighton Country Day School database – Autumn and Chaz Archerson's school – and gets a hit. They find Tim Swirsky at a pizzeria, and he tells them how he got into the party by taking Autumn's cousin. He wanted to get her back, so he spiked the punch. He just wanted to knock them down a peg, and he was kicked out immediately afterwards.
After questioning Tim, Stella runs into Mac in the lab. He remarks that he's also looking for a teenage suspect, and Stella says that the suspects are getting younger, but who do you blame – the kids or their parents? She asks Mac if he's heard from Reed – his newly discovered stepson – and he says he hasn't. Mac says Reed reminds him of Claire, and that he'll call when he's ready. Mac says he can't imagine how Reed feels, to spend all this time looking for his biological mother only to find out that she no longer exists. "She exists, Mac," Stella tells him. "In your memory, in your heart."
Meanwhile, Danny tries different types of power saws, trying to locate the exact one used in Ray Seeley's murder. When he gets a match, he calls Mac. Danny tells him that Jesse has access to power tools, his prints are all over the crime scene, and he has motive. "Still don't think this kid did it?" Danny asks. Mac insists that Jesse's not a killer, but tells Danny to call the DA and get a search warrant. They'll try and find out if one of the Quinns' power saws is their murder weapon.
Hawkes has been working with the photos he took of the car hood – all at various lighting angles – to determine what made the scratches. It turns out they come from a Greek coin, which was actually part of a coin belt – like the kind that belly dancers were. The theme of the party was Arabian Nights. So Hawkes contacted the party's photographer to get his flash card and look for all the girls who were dressed as belly dancers. It leads them to Paige, Autumn's best friend, who calls Archerson by his first name and says that he liked her and she just wanted into the party. She wasn't invited to the party because Autumn caught the two of them together, and the car was what it cost for her not to tell her mother.
Flack finds Mac in his office. The DA has been hassling him about the Seeley investigation, so he needs to know what's going on. Mac tells him that the blood on the crate was pigeon blood. When Flack asks about the warrant for the saws, Mac tells him that he's not going to rush things just because Jesse looks guilty. Mac details Jesse's history of abuse at the hands of his stepfather and says that he wasn't running from them, he was running from his stepfather. Danny comes in and informs them that he found Seeley's blood on one of the Quinns' saws and both Jesse and his stepfather's prints. Flack insists that the stepfather has no motive; Seeley was selling his flock, and Jesse got angry, so he killed him. Danny tosses the file on the desk and leaves. Mac asks for one hour to prove that Jesse didn't do it, or he'll arrest the kid himself.
Lindsay, back at work after her rush to the emergency room, has been examining photos taken from the party. She thinks she found the owner of the mystery hair Hawkes found in the car. It belongs to Mrs. Archerson. The same photographer took the Archerson's holiday photo, where Mrs. Archerson had much shorter hair – just two weeks prior. The hair extension is long enough to fit around her husband's neck and soft enough to have not done any visible damage. They just found their murder weapon and murderer.
Stella confronts Mrs. Archerson, who vehemently denies having anything to do with her husband's death. Her hair was in the car because her husband wanted her to look at it before the big presentation. When Stella tells her that her hair extension was the murder weapon, Mrs. Archerson says that she was with her daughter when her husband was killed. She then starts complaining about how the whole day was just one thing after another, and then she reveals that she thought the car was a bit excessive. They had agreed on a Mustang, and he bought Autumn a Mercedes Benz, because it was she wanted. "Well, they can't have everything they want!" Mrs. Archerson screams. She insists that she's not like them. That she just wanted to walk out and leave everything, including her daughter. She doesn't even like the name – it was her husband's idea. He had her sit in the car and see how comfortable it was. He told her that you only turn sixteen once, and she should just be happy. So she killed him. She says it was the right thing to do, that now the kids won't take the little things for granted and will be better off.
Agent Broadbent calls Mac. She says she may have something on the Seeley case. They agree to meet the next morning, at the Westway Diner at 8. Danny comes in, answering Mac's page. Mac thinks he can prove that Jesse didn't kill Seeley. Approximate time of death was 3 pm, and the pigeon they found landed at the coop at 3:18, after traveling a distance of 12 miles – a zone that includes the billiards shop where Jesse works. Danny realizes what Mac is saying – that 18 minutes was not enough time for Jesse to kill Seeley, make it back to the shop, and then release the pigeon. But, it all depends on how fast the bird can fly.
"Houston, we have liftoff." Danny releases the pigeon along the 12-mile radius line. Mac and Flack wait on Seeley's roof with a stopwatch. About 13 minutes later, the pigeon lands in front of them. Flack realizes that it would have only left Jesse 5 minutes to get from the murder scene to the shop, 12 miles away. So that means that Jesse's stepfather is the killer.
Flack and Mac interrogate Quinn. Mac guesses what happened – that Quinn went to Seeley's, dumped bug poison on the bird feed, and started to take apart the coop, which is when Seeley came back. Quinn killed him, knocking him into the coop, releasing the birds. And when Mac and Flack came to talk to Jesse, he ran away from him. Mac then lays out photographs detailing Jesse's many injuries. Quinn exclaims that life isn't a free ride – that Jesse spent all his time with Seeley and those birds. Jesse has a responsibility to him. He didn't even go to school, but he was fine letting Quinn work his fingers to the bone. "To hell with him," Quinn says, "and to hell with you." He says he should have tossed Jesse on the street years ago. Mac tells him that he would give a year's pay for two minutes alone with Quinn, but he'll have to settle for sending him to jail for the rest of his life.
Mac takes the one surviving pigeon – Sadie – back to Jesse. He says that his and Seeley's argument was because he used the elevator instead of the stairs – the feed leaked and the neighbors complained. He tells Mac that Sadie was his mom's name, and that after she was the only one who survived, he took it as a sign. Mac and Jesse watch Sadie fly.
Later that night, Mac goes to Reed's house. Mac insists on taking Reed out for cheeseburgers. Reed says that Mac doesn't have to buy him things because he feels bad. Mac says that he's not there for either of them – he's there for Claire. She would have wanted them to get to know each other, Mac says. He then takes out some pictures he brought of Claire. As they're leaving, Mac gets beeped. Agent Broadbent was ambushed and killed on the way to her car. She was asking questions about Seeley and was obviously silenced. But by who?