At 2:00am in the middle of a rainy and stormy night, 14-year-old teenage blonde Lana Walker is awake in bed and spots someone out her bedroom window. She faces her kidnapper mere moments later. Detective Yelina Salas briefs Lt. Horatio Caine that Lana and her 5-year-old sister, Molly, were both kidnapped. Yelina notes that murders occur within the first three hours of the kidnapping.
John Walker, the father, is upstairs in his girls' bedroom calling to prepare for a possible ransom demand. Horatio tells John to go downstairs so he can process his daughters' bedroom and find traces of their kidnapper.
Horatio finds only one set of footprints on the floor. He deduces that since only one person came through and broke into their room, the kidnapper could not have kidnapped both girls. Molly has to be around somewhere. Instinctively, Horatio walks to the laundry room and finds Molly hiding in the dryer. She whispers in Horatio's ear that a monster took her sister.
Into the morning hours, CSIs Tim Speedle and Calleigh Duquesne process the girls' bedroom. Calleigh swabs the bloodstain left on the bed. The blood pattern, had blood clotting, is circular and pooled around a specific point on the middle of the bed, which suggests that Lana was not attacked, but had a menstrual cycle. Horatio finds an oil smudge on the window, which could have possible come from the nose or the forehead, meaning the kidnapper peeked in from the window. A shiny purple fiber was found on the window frame. Speed collects it for Trace later.
Eric Delko is outside taking John's fingerprints. He briefs John that the FBI is involved in her rescue. Eric instructs John to put together a list of his and his wife Krista's most recent contacts. Meanwhile, Horatio interviews Krista, who tells her youngest son and daughter to hang out with their daddy at Eric's truck. Horatio asks for personal things that Lana uses daily to track and identify her. Krista demands fives minutes alone with the kidnapper. Horatio asks Krista to call him when she can think of something pertinent to the case. He also instructs the Walkers to find another place to stay since their home has been declared a crime scene.
The news issue a missing persons alert for Lana Walker. The news reports that Lana is a junior tennis champion. Speed catches resident Willy Camp near his crime scene truck. Willy reminded Speed that the police are using his garage as a command post. Speed tells him to back off. Police print posters from the garage. Eric retrieves clothes from Lana's closet. Nothing in the Walkers' home match the purple fiber, meaning it originated from Lana's kidnapper. Horatio asks Eric to pass out the posters. Yelina walks into the garage and reports to Horatio that there are 15 registered sex offenders living in a 10-block radius from the Walkers' home. Willy Camp is one of them.
Horatio interrogates Willy about Lana, showing him Willy's photos of Lana playing with her siblings. Willy explains that he is part of Neighborhood Watch and is supposed to document suspicious activity in the neighborhood. Horation reminds him that possession of material relevant to his sexual deviant behavior is prohibited. Yelina comes back with more of Willy's photos, showing only the young Walker boy in his shorts only while playing in the sprinkler. Further background investigation shows that Willy's sexual tendencies are towards young boys. Eric alerts Horatio on the phone that traces of Lana was found in quadrant three, which is in a swamp area.
A severed human arm is found in quadrant three. Yelina prepares to call Emergency Services to call off the search teams, but Horatio tells her to double them since the kidnapping situation has been escalated. Speed meets with Calleigh to tell her that knock-and-talk patrols found witnesses up the street from the Walkers' home, saying they saw a car speed away after midnight. The witnesses gave them their home video tape. Calleigh and Speed watch it and watch them have sex. Some of the staff walk in with thin excuses to watch the sex tape and Calleigh jokingly asks if they would like a copy of the tape. They hear the car pull away. Calleigh notices the background noise and both hear that the car bumped into something leaving the scene.
Calleigh and Speed revisit the scene and find fiberglass in the hole the car ran into. They identify the glass as coming from a red convertible. Calleigh tells Speed to examine the glass while she reexamines the tape.
Horatio and ME Alexx Woods examine the severed arm and find a tooth where the elbow used to be. Eric identifies it as an alligator tooth, meaning its original owner was fed to the alligators. Alexx prepares the arm to deliver to Histopath to process if the arm's owner lived or died before the arm was severed. Krista Walker pulls into the crime scene and demands to know if the arm belonged to her daughter. Horatio tells her he cannot discuss the case with her since it is still active. Krista tells Horatio to look into a man she had an affair with. His name is Art Pickering, who got angry at Krista after she ended their relationship a month ago. Art went to Lana's tennis matches, making him a suspect. Krista claimed that John had no knowledge of her affair. Before the relationship ended, Krista remembered that Art told her to "run back to your perfect little family." Horatio asks for Art's phone number.
Horatio and Yelina interrogate Art about his relationship with Krista. Art claimed they went out for a couple of months. He also claimed that Krista said her husband ignored her and she ran to Art. Horatio brought up Art's three domestic violence charges filed by his ex. He was also charged with kidnapping his own daughter, and Art defends this by saying they were on a legitimate vacation without his wife's consent. Police picked him up 500 miles from their home. Horatio receives a phone call from Speed, confirming the color of the glass is red and came from a convertible. He asks Art what color was his car, which is red. Horatio examines Art's Viper's trunk and finds a purple fiber similar to the one found on Lana's window.
Art is brought back to interrogation about the fiber found in his car. When Horatio shows Art pictures of both fiber strands, Art blinks and blinks and is unable to see what Horatio sees. Horatio asks if Art was recently treated for Vitamin A deficiency, to which Art replies "yes." He lets Art go because he figures out that Art has night blindness, making him unable to drive at night and is ruled out as a suspect.
Calleigh meets up with GMAC sound technician Todd Cunningham about the mystery car. His sound analysis indicates that the car has an aluminum block 8-cylinder engine or better, auto transmission, and low-grade octane gas not suited for the car due to its knocks and pings. After some time processing, they narrow the vehicle down to an LT-5 V-8, made by GM for Corvette to be added to the ZR1 series from 1990 to 1995. Calleigh issues an amber alert for the ZR1 Corvette.
A trucker found the car off of Highway 1 and the DMV matches the registration to David Kendall. Speed confirms that the car paint is a match to the glass found in the neighborhood. The car has damage where it bottomed out. SWAT prepare to move in on the motel where David is staying. Surprisingly, David walks outside carrying a bag of tennis rackets and eye shadow with no resistance. More surprisingly, Lana is alive and well, dressed in a white bath robe. Both are taken into custody for questioning.
Horatio and Yelina question Lana about her disappearance. Lana left the window unlocked for David to take her away so they can be together. They made love in the motel. Horatio warns her that David will be charged with statutory rape.
In a separate interview with the Walker parents, they explain that David was privately coaching Lana for two years every day before school, after school, and on the weekends. When Krista asked how long Lana was seeing David, Lana told Horatio it's been four months now. David was not among their most recent contacts because John fired him for not developing her tennis skills fast enough. He felt the parents' expectations were too high, even for a tennis family. David stayed because Lana called him to stay in touch. Yelina told David he would be charged for statutory rape, but David told them that Lana's parents lied about her age. John confirmed this, saying he wanted the best tutelage available for Lana. Krista attacked John verbally for wanting everything his way. John countered by bringing up her affair with Art. Horatio asks about Krista's age, which is 16 years of age. Yelina explains to the Walkers that at the age of 16, a person may have a sexual relationship with someone up to the age of 24. David is 23 years old, which makes their sexual relationship legal.
Art waves Horatio bye for now since they cannot legally hold him for statutory rape. Calleigh and Horatio decide to process the severed arm.
Calleigh and Speed process the arm with Alexx. Horatio arrives at the medical examiner's office. Speed was unable to determine where the arm may have been. The arm matches a teenage girl 5'4" to 5'6". The victim had symptoms of later epicondylitis, a.k.a. tennis elbow. The tissue was nonhemorragic, indicating she died before her arm was severed. Eric calls in to let Horatio know the canal search turned up nothing. He also said he was bringing in an old college buddy and alligator expert to help him with the search.
The expert is Jeff Corwin himself, who was a fraternity brother with Eric at University of Miami. Eric asks Jeff to help find the alligator tooth's owner. Jeff tells the CSIs they're not going to find the alligator because the tooth actually belongs to an American crocodile. They have migrated up north from the Florida Keys to a nuclear power plant due to the heat. All 3,000 crocodiles have migrated there.
Horatio arrives at Art's place and asks him about David Kendall. Art recognizes him as a tennis pro at his club. Horatio wants to know about the purple fibers in his car. He asks Art if he can look into the shed, and Art obliges. Horatio finds boxes of "Pickering's Rock and Stone" t-shirts with the same purple fibers. Art assures Horatio he gives them away as charity gifts. He obliges as well.
Horatio and Yelina arrive at a tennis club where aspiring tennis youth are practicing wearing Art's t-shirts. The club director told Yelina that David would coach once a week there for free. Horatio spots a missing persons poster for Consuela Valdez, with the word "desaparecida" (disappeared) appears on the top.
The two interview Francisco and Milagra Valdez, whose daughter disappeared three weeks ago. The parents remember David Kendall giving Consuela free tennis lessons. They also remember her wearing a sweatshirt with purple lettering. Horatio confirms that their daughter was the one murdered and fed to the crocodiles. Milagra believes that no one cares about her family, but Horatio disagreed, saying that he cared about them.
Calleigh, Speed, and Eric continue their search near the power plant in the swamps. Jeff instructs the search party about how to handle crocodiles. Since the crocodiles are listed as an endangered species, all of them have been implanted with a microchip. Eric instructs the search party to use the microchips' scanners to pass above the crocodiles' backs and use the digital display to read "0116", determined from the DNA from the crocodile's tooth. Eric and Jeff find the crocodile and contact Horatio and Alexx. Since the crocodile is an endangered species, Horatio suggests irrigating its stomach contents with water. They eventually find a severed foot damaged by the crocodile's stomach acids. They also find a tennis shoe and purple lettering from the stomach, positively identifying the victim as Consuela Valdez. Horatio deduces that the killer picked up fibers from Consuela's body and carried it to the Walkers' home. However, they still cannot identify who the killer is.
Eric is offended that a blond girl gets the National Guard and media attention when she is kidnapped while no one pays attention to a Hispanic girl being kidnapped. Calleigh notes that a lot of people turned up to help find Consuela. Eric asserts that to get attention, people need blonde hair and blue eyes. He apologizes to Calleigh for offending her, but Calleigh is not offended because her eyes are green.
Horatio catches David instructing Tiffany, another aspiring tennis player. He interrupts the lesson to accuse David of killing Consuela. Horatio points out that David transferred purple fibers from Consuela's sweater to Lana's bedroom window. Horatio ends the lesson and takes Tiffany away from David.
Yelina talks with Krista about Lana running away again. Krista believes that David took her away, but Yelina tells her the law is about what can be proven. She escorts Krista to Missing Persons.
Alexx finds binding on Consuela's severed ankles. Calleigh collects them and recognizes them as tennis strings with the same color matching them. She matches strings against David's strings from his bag, which do not match. Horatio remembers the Valdez parents saying that David brought gifts for their daughter. Francisco brings out Consuela's tennis rackets, which have the same color as the strings binding her feet.
Eric and Speed process the strings from the rackets and match the strings to Consuela's bindings. Horatio alerts Yelina that he has forensic evidence pointing David as the killer. Yelina told Horatio that she recently filed a missing persons report with Krista. Horatio races down to David's house to stop Krista from dealing with David herself.
Horatio arrives in the nick of time to stop Krista from shooting David. David is holding Lana with his forearm around her neck. Horatio has his gun drawn on David. Lana insists that they are in love, but Horatio tells her that he will be going to a memorial for Consuela, who was killed by David. When Horatio tells David to tell Lana how he killed Consuela, David is frozen. Lana walks away from him and the police apprehend David for Consuela's murder.
A memorial is held at the marshes where Consuela's remains were found. Horatio and the CSIs were there to toss white roses into the waters in Consuela's memory. News Reporter Jake Grant approaches Horatio for his story about his involvement in the arrest of David Kendall. Horatio gives Jake a list of names for five black girls and seven Hispanic girls who disappeared and never made it to TV news. Jake replies "What's your point?" Horatio replies while putting on his sunglasses "What's my point? Make it your next story!" Horatio walks away.