Two girls are walking down the street and discussing their bad luck with finding good men. One complains that there are no more good guys in the world. As if on cue, a man in boxer shorts falls down from the sky and is killed when he hits a glass stand. The two girls begin screaming.
The next day, the CSIs show up. Greg notes that the victim has a demolished skull and that there is a smell of alcohol in the air- indicative of the possibility that the man was drunk and fell from the hotel/casino building that overlooks the street. Ray notes that the injuries that the victim sustained could have come from a fall of any reasonable height. Nick interrogates the two girls who saw the man fall (and collects brain samples from the chest of one of the girls). Neither of them claims to know anything about the victim. Catherine talks to a man named Jared and finds out that the man's name was Brad Malone, he owed over $100,000 to the casino, and he was in room 730. Detective Vartann witnesses Catherine hug Jared and jealously asks her why she hugged the man. Catherine nonchalantly tells the man that when Sam Braun died, he left her a portion of the casino and that she knows several of the workers there. Detective Vartann is still jealous and Catherine rebuffs him, not wanting to discuss her shares in the casino. She goes over to Nick, Ray, and Greg and tells them what she discovered about the victim. The four muse over the theory that, since the man was up to neck in debt, he came to the casino for one last hurrah before committing suicide.
Nick and Ray go into Brad's room and go over his personal life and assets. He was divorced twice, had no kids, was up to his ear in overdue loans, apparently spent his last night alone (as there are no signs of anyone else in the room), and had all of his personal effects lined up neatly in his room. Nick points out that this is all consistent with a suicide, but Ray states that there is no suicide note. Ray also points out that the locking mechanism on Brad's window (which can only be locked from the inside) has been activated, raising the question of who locked Brad's window after Brad was killed. Ray then dusts the window screen and gets a fingerprint.
Jim takes Greg and Sara over the scene of a double homicide: that of the Irwins. Mrs. Irwin is lying inside of a broken table with multiple stab wounds. She was reported to have dialed 911 but was only able to say, "someone help me" before the line went dead. Mr. Irwin is tangled up in a shower curtain, lying facedown in the shower. His extremities show discoloration. Greg surmises that the killer first surprised Mrs. Irwin, killed her, and then took care of Mr. Irwin while he was in the shower. Jim tells them that the window is open and the screen was torn, revealing the killer's entrance. Greg notes that there is a family portrait including a cat and a parrot. The parrot is in the house, but the cat isn't. Sara also realizes that all of the cash and credit cards are in the house, and the parrot (which would probably sell for thousands of dollars) is still in its cage. The motive was not robbery. Jim decides to round up the landlord of the apartment in which the Irwins were situated in order to find out if they had any enemies. Greg and Sara take blood samples from around the house.
Ray tells Nick that the fingerprint found on the balcony belongs to Brad Malone and that the shoe prints found near the window are size tens, the kind that Brad wore. Nick notes that Brad may have been pushed from a different room. He looks out and realizes for the first time that the area where the body landed is consistent with a fall from the room right across from Brad's. Detective Vartann shows up and tells the two that the room in question was registered to two girls named Stacey and Dana. The three men call for the girls to open the doors and, when there is no answer, use an all-access card to get in. Nick notes a blood trail on the floor leading to the bed that the girls share. Both girls are in the bed and covered in blood. When Ray tries to touch one of the corpses, the girl reaches out and grabs his hand. Both girls are revealed to be alive.
Nick and Ray interrogate the two girls and Ray points out that, though they have some minor bruises, they have no open wounds and the blood on them is not their own. Nick shows them a picture of Brad and asks if the girls remember him. They answer negatively but point out that they had a lot to drink the previous night and don't remember much. When they ask what happened to Brad and find out that he's dead, one of them begins to vomit. Nick gets them admitted to a hospital but tells them that there will be more questions.
Sara and Dr. Robins go over the corpse of Mr. Irwin and find that the man was knocked unconscious by a head bump to the wall. Then he drowned in the bathtub water, which later all went down the drain. There are also closed scar wounds, likely from a previous altercation. Jim interrogates Dwayne, a neighbor of the Irwins who was very upset with them and threatened to kill them in a voice message that he had left on their phone. The man tells Jim that the only reason that he was upset was because the Irwins were always arguing and their parrot was always squawking. When Jim asks him what he was doing the day of the murder, Dwayne says that he was having phone sex with a girl named Betsy. Jim asks for her number.
Nick and Ray go over Stacey and Dana's room, marking out signs of sexual activity, while Catherine interrogates Stacey and Dana while they are in the hospital. Stacey tells Catherine that she remembers only small bits of the night before. She went to a club, and the last thing she remembers is drinking from a large tube. She also says that she was partying with Stacey in celebration of finally having gotten a divorce settled with her ex-husband after a one-year debate. Dana tells Catherine that she remembers nothing. Catherine points out that they both test positive for having engaged n sexual activity on the night of Brad's death and asks if (since Brad was a good looking person) the girls perhaps invited Brad into their room for drinks and sex. Dana cries, upset because she was in a loving relationship with her husband and had never slept with anyone before or since him. Catherine promises to help her figure things out. Ray explains to Nick that, since alcohol affects judgment and memory, it is quite possible that the girls remember nothing of the previous night. Ray finds an iron under the bed with blood on it. He theorizes that one of the girls might have gotten upset over something that Brad said or did and hit him with the iron. The other girl helped to dump the body out of the window and get rid of the evidence.
Greg catches up with Sara and tells her that he spoke with the landlord and the screen that was broken out was from one of Brad's rages in which he punched it out. Sara theorizes that perhaps there was no intruder. The Irwins had a fight. Mr. Irwin stabbed his wife, tried to clean the blood off of him in the shower, slipped, knocked himself out, and drowned. She also points out that, if the theory is right, then Mr. Irwin's fingerprints will be on the knife and Mrs. Irwin's blood will be in the shower.
Ray and Dr. Robins go over the body of Brad Malone. Dr. Robins shows Ray drag marks on Brad's buttocks and thighs (that contain paint flecks from the railing of the eclipse hotel/casino) that are consistent with being thrown backwards over the edge of a railing. He also shows Ray marks on Brad's arms that are consistent with fingernail scratches and tests that reveal that Brad did have sex on the night of his death. Ray tells Dr. Robins that this is consistent with a used condom that was found in Stacey and Dana's room. Ray then theorizes that Brad may have gotten too pushy with one of the girls, didn't want to use a condom, and the girl defended herself by hitting him with the iron. Both girls then pushed him out of the window when the iron wouldn't stop him. Nick later shows Catherine Brad's pants, the bed sheets from the girls' room, and the carpet, which all contain blood from another unidentified male: the three-way sex party was actually a four-way.
Greg and Sara go back to the Irwins' house and do not find Mrs. Irwin's blood in the shower or Mr. Irwin's fingerprints on the knife. Greg decides to take the parrot back to the lab as evidence. He then goes into the drain of the shower to see if he can find Mrs. Irwin's blood in there. He finds hair and feathers, both with blood on them. It seems that the Irwins not only fed and dressed their parrot, but they gave him showers too. Sara sees that the crime scene has been contaminated and notices paw prints. She looks under the couch and finds the elusive pet cat. She summons the cat in order to take it back as evidence as well.
Catherine and Detective Vartann go over the Brad Malone case so far. Catherine grows extremely upset over Vartann's inability to sympathize with the fact that the girls were drugged and didn't know what went on the night of the murder. When he asks why she was that upset, she explains that the same type of scenario that happened to them happened to her a few years ago, only she wasn't raped. The two share a tender moment, which Nick later interrupts by entering with the doctor's report for both girls. There was enough vaginal fluid and semen to prove that Stacey had unprotected sex with Brad on the floor and the table. Both of the girls drank from drugged drinks. But only Dana had enough alcohol to have caused memory loss. Detective Vartann guarantees Catherine that Stacey knows more about the night of the murder than she's telling. Vartann and Catherine interrogate Stacey and demand the truth from her. She says that her and Dana met a mystery man named Kyle and invited him to drink and dance with them. Kyle later came back to their room and Brad showed up to request that they turn the music down. Dana invited Brad in for a drink and then went into the bedroom with Kyle. Brad then raped Stacey on the floor and the table. Dana finished up in the bedroom with Kyle and then Kyle forced Stacey onto the floor, claiming that it was his turn to have sex with her. When Brad showed up in the room, Kyle, who had gone ballistic, pushed Brad until he fell out of the window. He then ordered the two girls to go to bed, swearing to kill them if they said anything to anyone about the murder.
Ray goes over the case with Catherine and points out that he still has his doubts about the story that Stacey told Catherine and Detective Vartann. David calls Ray into his office and shows him some evidence that he has recently gathered. It seems that the feathers from the beds in the girls' room came from two different areas. One was natural for the casino bedrooms. The other came from a pajama bar called the Pillow Room. Nick and Ray go to check the place out. They discover that Kyle is a bartender there. Ray pulls a bandage from his head, revealing a wound consistent with an iron. Ray and Nick then take Kyle to the station for interrogation. Kyle swears that he didn't kill anyone. When Ray asked what happened, he claims that the girls wanted to get high, so he gave them the drugs that they asked for. They partied with him and then he tried to have sex with Dana in the girls' room. Dana refused and hit him with the iron and chased him out of the room. Brad then showed up, asked Dana if she was okay, and forcefully kept Kyle away from the girls. Kyle went to the hospital to get stitched up afterwards. Nick promises Kyle that he intends to call the hospital in order to verify the story.
Dr. Robins shows Sara the body of Mrs. Irwin. He points out that she died by a single stab wound and that only her prints are on the knife: Mr. Irwin didn't kill his wife. He also shows her scalp lacerations on Mrs. Irwin's head, consistent with the fact that the parrot scratched her. Sara asks how it was possible for the bird to get out of, then back into the cage and Dr. Robins tells her that birds are smart and can be trained to do almost anything. Catherine asserts that it is ludicrous to assume that the parrot is a suspect in the murders.
Sara goes to Hodges (who reveals that he has a fear of birds), who shows her that the parrot and cat hate each other, and decides that they should process the animals. After the processing is complete, Sara finds Mrs. Irwin's skin under the bird's talons and blood under its wings. David finds plastic from the shower in the cat's claws. The two go to Jim and present their idea of what happened. Mr. Irwin was giving the parrot a shower. The cat (who hated the parrot) ran in and attacked the parrot. In the commotion, Mr. Irwin slipped, was wrapped in the shower curtain, knocked himself out on the wall, and drowned himself. Mrs. Irwin, who was making breakfast, came into the shower to see what was going on. The parrot, still in an aggressive mood, attacked Mrs. Irwin and scratched her (splattering blood on the walls when it flapped its wings). Mrs. Irwin fell into the table and stabbed herself in the process. The bird locked itself back in the cage, and the cat went into hiding. Jim tells them that he believes that their story makes perfect sense. Sara says that the only thing that doesn't make sense is how Mrs. Irwin, who had blood on her hands, was able to call the police and leave no blood on the phone.
Nick and Catherine go over the Brad Malone case and Nick points out that the Bartender's story does check out: Dana was lying. Catherine, Nick, and Ray do a railing test to see if Catherine (a woman of Dana's size) would be able to push a man of Brad's size (Ray) over the side of a building. The test proves positive, but doesn't leave enough scratches on Ray's thighs to prove murder. The three try another test in which Ray is sitting on the railing and falls accidentally while Catherine is in his lap (testing the theory that the prints on the balcony were toe prints, Dana and Brad were having sex on the balcony, and then Brad fell off of the railing). That test does prove positive. Catherine re-interrogates Stacey and tells her what really happened on the night of Brad's death. Dana and Brad were having passionate sex. The sex got out of control and moved to the balcony. Brad then accidentally fell off of the balcony while Dana was in his lap. Dana tried to stop the fall and scratched Brad in the process. Dana admits that this was the truth and says that she is ashamed hat she slept with someone other than her husband. She says that her and her husband only have sex twice a month and that her connection with Brad, a perfect stranger, was so strong that she couldn't help herself. Catherine tells Dana that she will not be charged, but she still has a lot of explaining to do to her husband and should probably leave out the part about her strong connection to Brad.
Catherine later meets up with Detective Vartann and tells him that she is sorry for keeping secrts from him but that she doesn't believe that couples have to tell each other everything. Vartann asks her who gets to draw the line and asserts that facts such as owning a part of a casino are relatively large secrets to keep from people. Catherine tells him that she is who she is, tells him to call her when he can decide whether or not to accept her, and walks out.
Greg and Sara find the parrot a new home with a nice family, no cats, and another bird. Greg accidentally cuts his finger with a knife. The bird, seeing the blood, picks up the phone, dials 911, and says, "Help me! Help me!" Sara realizes that this was how the police were phoned when Mrs. Irwin died.