A man and a woman in business attire start making love in a bungalow when the woman hears strange sounds. The man assures her they're just the sounds of ocean waves. She notices something amiss anyway. She checks further and finds flies buzzing from underneath the bed. As the man continues to undress, the woman finds the body of a woman apparently rotting underneath.
CSI Lieutenant Horatio and Detective Christian Brunner arrive at the scene. Officers on the scene lifted the bed and investigate the body underneath the bed. The victim, found naked, is Susan McCreary, who had priors for prostitution. Her pocketbook and clothes were missing from the scene. Susan was sent to pay the hotel clerk for the booking. A cleaning maid had missed the body in her routine cleaning. Investigation begins.
At the time the body was found, the temperature of the room was 75 degrees Fahrenheit. Medical Examiner Alexx Woods combines the room temperature with Susan's liver temperature to ballpark time of death between 7:00pm and 9:00pm last evening. Repeated stab wounds were found to have been made with a slim and sharp object, consistent with many possible sharp objects. No blood was found on the floor and the she could not have been stabbed from underneath the bed. Alexx believed that she was stabbed on the bed. No blood was found on any of the furniture. Tim Speedle got the bedsheets from the maid and reported no visible stains. Horatio asked him to bag the bedspread as well for further investigation at the lab. Using a green UV light, Horatio detected blood spatter on the wall, indicating that the victim was stabbed in the room and the killer tried to clean it up. Alexx also detected a hint of cardamom, a cooking spice. It's also used in scented soaps. Tim reported that the maid noticed some towels and a washcloth was missing from from the room, along with some scented soap. Horatio asked Speed to shine the UV light on the tub. They discovered some bars of cardamom soap among the bathroom's toiletries. Tim spotted large trace amounts of blood in the tub, indicating that Susan was washed after she was killed. Detective Brunner returned to the crime scene with a handful of Susan's belongings found in the hotel dumpster. Speed decides to check the dumpster next after completing his investigation in the hotel room.
Elsewhere, CSIs Eric Delko and Calleigh Duquesne arrive at a gas station where Detective Adell Sevilla is investigating an attempted carjacking/robbery. A German tourist couple were the victims, where the wife is in tears. Sevilla briefs the CSIs about the wife's story: a masked man approached their car and shot the husband. The husband fled and the shooter fled after him. The strange part is that the masked man continued to chase after the husband, killed him, and left his body at the garage bay. Eric investigates the garage while Calleigh investigates the car.
Calleigh's investigation: A stain is left on the rear-view mirror, which Calleigh collects. She also noticed security cameras that pointed downwards at the car at the time the crime was reported. Calleigh detected the blood spatter in the car.
Eric's investigation: The husband was found face down on a pool of blood. Eric saw one entrance wound close to the mouth. The blood pattern in the garage showed a visible print, but not determinable if the print was left by a shoe. High-velocity blood spatter was found on the back of a Nissan truck. The position of the body along with the blood patterns make it difficult for the CSIs how exactly the murder went down.
At the Miami-Dade PD morgue, Horatio and Alexx counted 23 stab wounds on Susan, some of them which were tentative, meaning the killer was possibly inexperienced. Most of the impressions were deep. Cause of death was exsanguination from sharp-force injury that severed the aorta. The aorta bled into the chest cavity after it was struck, which helped with the killer's clean up job. Adhesive was found on her wrists, ankles and mouth, indicating she was bound and gagged during her death. No signs of sexual trauma was found. Horatio believes that the killer just wanted to kill for the pleasure of it.
Tim's search of the hotel dumpster revealed the victim's clothes. Pipes from the tub came up empty, but drain cleaner was used to cover the killer's tracks. A stain was found on the bedspread.
Horatio begins scanning through Susan's personal effects. A fingerprint was found on her belt. The fingerprint was a match to Cole Judson. The smear on the bedspread was some kind of mold not applicable to anywhere in the crime scene. Cole Judson was arrested earlier on stabbing charges.
Horatio and Brunner arrive at Cole Judson's residence. They arrest Cole, but not before asking his wife, Wendy to call his lawyer. Wendy protested the arrest, but Horatio presented to her a warrant to search Cole's residence.
Eric and Calleigh view the surveillance footage pulled from the gas station. The killer is masked, but they match the killer's fingerprint to the blood smear found in the garage.
Alexx retrieved two bullets from the body. The kill shot was found fragmented, but the first shot was found completely intact in the victim's mouth, shattering his front teeth and lodging its way through his tongue and into his throat. The high-velocity spatter was found to have come from his mouth when he tried to hide from his killer.
Horatio and Speed search Cole's home, turning up kitchen knives, scissors, and other family trinkets. Outside, the CSIs observe Wendy's ex-husband, Michael Giotti, comforting their kids and taking them away from the house for their safety. Wendy agrees to this willingly. When asked about Cole's priors, Wendy denies this, believing that Cole is incapable of assaulting women. She claimed that on the night of the murder, Cole was at a weekly sales meeting until 9:00pm.
Brunner runs down Wendy's contact, who claimed that Cole did not show up at the late-night sales meeting, since he does not work that late at all. They interrogate Cole, who had a bandage on his index finger. He claimed that his stepson, Henry, put it on for him because he whacked it accidently. On the night of the murder, Cole claimed to take his nightly walk on the beach. Horatio points this out as an inconsistency with his wife's statement. He admits to being selfish, wanting to have a night to himself. When asked about his priors, Cole recollects his time in college with Beth, the alleged victim. He claimed that they went out, got drunk, and she cut herself. After being checked into the ER, Beth claimed that Cole cut her in order to save face with her parents. When shown a photo of Susan McCreary's dead body, Cole looked visibly sickened, but denies knowing her. Horatio excuses himself from the interrogation room.
Calleigh analyzes bullet striations from the male German tourist. They match striations from bullets found in an earlier gas station robbery. She updates Adell with this information, but Adell tells her and Eric that the adult suspect is currently in jail for that earlier robbery. The gun was never recovered. The suspect had a juvenile accomplice, who only served a few months before being released. The juvie's name is Malcolm Davidson, who is staying at his grandmother's.
At the Davidsons' residence, Calleigh and Adell question Malcolm and his grandmother, who claimed that Malcolm was with her at the time of the carjacking. Eric discovers a glove in Malcolm's closet, which is similar to the one found in the surveillance footage. The glove has a pattern similar to the blood pattern found on the floor of the garage bay. Malcolm is arrested while his brother protested his involvement in the robbery.
Horatio tries to recreate the circumstances of the hotel crime scene using the bedding from the night of the murder. He asserts that the killer tried to clean up, but somehow, some blood escaped his cleanup. Using beef blood, which is closely similar to human blood, Horatio determines that the fingerprint found on Susan's belt was not formed with her blood. The print was oil based with the victim's blood applied later. Allowing the blood to flow down to the furrows of the fingerprint, the killer succeeded in framing Cole Judson, who will serve time for Murder One if Horatio and Speed do not clear him. The District Attorney would not be able to convince a jury of this because people understood fingerprints well, and a study made by a fellow CSI out of state would confound their decisions further.
Horatio deduces that the killer left mold that contains the incriminating DNA. The mold is a match to shower curtains found in Cole's home. Horatio concludes that by distilling the mold to the killer's DNA is the only chance of saving Cole from doing time in Death Row.
Calleigh and Eric meet up at the evidence locker. Eric found Malcolm's epithelials, the German husband's blood, and a waxy substance. Its chemical compounds are identified as lipstick, which came from Malcolm's grandmother kissing him before he left. The lipstick is also a match to the smear in the car's rear-view mirror, furthering the possibility that Malcolm was at the rental car. The video showed that Malcolm never entered their car, but they believe that Malcolm was in the car earlier. Their next step is to figure out who Malcolm was with at the time.
Horatio reports his findings to Brunner, who is surprised to hear the news. Brunner doesn't believe him, but Horatio pursues the angle further. He meets with Cole, who is currently in custody, and asks about who has access to his apartment. He also asks Cole who would want to hurt them. Cole remembers seeing Wendy's Michael, who was in their apartment when 1) he didn't have access to the apartment and 2) he came at a strange time. Horatio and Brunner question Michael, who claimed to have custody that day when Horatio caught him in that lie. At the time of his break in, the ex claimed to search for drugs, pornography, and other incriminating evidence on Cole. Three days after their divorce, Wendy married Cole, who were seeing each other five months before and Michael got suspicious. Michael claimed to have been at a cocktail party as the toast master at the time of the murder. After the interrogation, Horatio realizes that the time of death may have been skewed due to the room temperature of the bungalow.
Earlier in their investigation at the crime scene, Horatio took note of orchids in the bungalow. At the time of the discovery of Susan's body, they noted that the room was 75 degrees Fahrenheit, which is optimal temperature for humans and orchids. He points out that some of the orchid petals have been wilted due to a drop in room temperature, meaning the orchids were chilled along with the body. The time of death is currently the only factor that places Cole in the bungalow and clears Michael of any wrongdoing. The CSIs deduce that the killer returned to the room sometime after the murder to restore the thermostat to the optimal room temperature level after chilling for sometime below 55 degrees Fahrenheit.
Calleigh and Adell question the German wife, who was not able to pick out the shooter in some photos. The wife claims to not know the shooter since he wore a ski mask. She is visibly saddened and panicked, wanting to return to Germany with her husband's body. Calleigh offers her a glass of water and she accepts. She sips the water and sets it down. The wife claims to be tired, so they excuse her. From the glass, Calleigh collects the wife's DNA along with a sample of her lipstick and her fingerprints as well.
Horatio meets up with Alexx, who is convinced of the bungalow's room temperature being manipulated to throw off the time of death. Speed confirmed with an electrical company that a spike of kilowatts occurred between the hours of 9pm and midnight on the night of the murder. The killer chilled the room for a while, then returned to the bungalow to reset the thermostat in an attempt to implicate Cole. The newly-established time of death clears Cole and narrows the suspect pool to Michael.
Horatio asks Speed about how much evidence is overlooked in a career. Speed replies in regards to Horatio that he overlooks very little evidence and because of that, Speed misses very little. They both agree that a fingerprint would be the perfect clue to finger Cole as the murderer. With Cole's conviction, it would be straightforward to frame Cole for Susan's murder. In fact, they realize that the killer had more information than needed to frame Cole, meaning that Michael had researched Cole thoroughly enough to frame him with. They decide to track down his information source.
Calleigh processes the lipstick, which is a match to the rear-view mirror, but not to the gloves because of the differing shades that Grandma Davidson and the German wife wear.
They deduce that the carjacking was actually a hired hit. Eric noted from auto insurance studies that it takes an average human 1.5 seconds to respond through sensations to actions being taken against them. For unexpected stimulus, the brain requires more time to process. From the surveillance footage, the wife, Greta Roebling, ducked down 1.1 seconds after the masked gunman drew his gun on the couple, indicating that the Greta had prior knowledge of the shooter's intentions.
The shooter is revealed to be Malcolm's older brother, Brian. Adell told Brian that the Florida State Department furnish his information to them about his time spent in Germany, including his work visa, proving that he spent time in Germany as a resident. More specifically, Stuttgart, where Brian was a dancer at the Stuttgart ballet. The lipstick is a match to a European manufacturer in Germany. After the ballet cut him, Brian started teaching private lessons, where one of his clients happened to be Greta Roebling. Greta agreed to cooperate with the police under the threat of the death penalty. Greta claimed to being lazy, not enjoying dancing, not even exercising. Greta claimed to have joked about wishing her husband dead, but didn't really mean it. Brian claimed that Greta handed him $10,000 and an itinerary to arrange for Mr. Roebling's death. He asked Malcolm for a fresh gun, but ended up giving him the gun used in an earlier robbery instead.
Speed tracked down a purchase made at a criminal records company. It was revealed that Lee Bastille, Cole's landlord, purchased information on Cole's criminal record. Horatio believes that Lee used this information to frame Cole.
Horatio and Brunner question Mrs. Bastille. She told them that Lee owned the building for four years, but did not know Cole. She claimed to have made a credit check on Cole. They manage the building together. During the questioning, Horatio finds a book on bloodstains, which belongs to Lee. He excuses himself to the bathroom and finds the cardamom soap, which came from the hotel bungalow. Mrs. Bastille came into the bathroom to check on Horatio, who claimed that Lee brought the soap home. Horatio asked her if Lee asked her to use the soap. He had used the soap in her baths. Horatio asked for her alibi, to which she responded that they had dinner every night at 7pm, but he was called by tenants about broken pipes. She claimed that the call was made sometime before 9pm, but she does not remember a phone ringing. Mrs. Bastille is visibly shaken at what her husband might be, worried that he'll be home soon with the police. Horatio asks to search her apartment but taking her to a safe place first.
Horatio continues to search the apartment, collecting the cardamom soap and some molding. He finds some plumber's putty, which was used to form Cole's fingerprint. Lee was taken into question later. Cole's fingerprint transferred into Lee's plumber's putty, which he stored for later use. Horatio had founded traces of epoxy, which casted Cole's fingerprint for use later in the hotel bungalow. Lee continually denied his involvement, but Horatio pointed out that the mold from his shower walls matched the mold from the bedspread.
Lee could not deny his crime any further. He felt dead because he made the same routine day after day. Lee justified killing Susan to learn how to live life again. He defended his actions, denying that he was a monster. Horatio strongly disagreed with Lee on this aspect.
Cole is released from prison and freed of involvement with Susan's murder. Horatio drives him home to reunite him with Wendy and his stepsons. Cole waves him farewell before leaving.