Four miles south of Mamala Bay, a group of young people are partying on a small sailboat having a blast. The man at the wheel offers the girl next to him, Susan who is turning the sail to work, the wheel for a while which excites her. She watches as the passengers pose for each other's cameras. One boy is taking a video of his friends when the Captain notices a group of people dressed in black with masks heading towards them in a smaller boat. As they come up next to the sailboat, they start shooting at the sail and the Captain tells Susan to get everyone below deck. The masked men fight off some of the male passengers as they try to take control of the sailboat. The Captain then draws a gun but one of the masked men guns him down. They take everyone below deck, leaving the cell phone that has them filmed lying on the deck.
Steve and Danny are pushing Steve's dad's car up a hill. Danny gripes that Steve has been working on the car for six months and it only lasted nine miles. Steve tells him it is an old car and they are temperamental, and Danny argues cars are not temperamental but that they are just machines. Danny gets frustrated that Steve wants another twenty feet before leaving the car. As the tow truck pulls up, Steve gets a call that they are needed at the coast guard station. Danny tells the tow truck driver that he needs a lift, but Steve needs help.
As they head out on the water, Steve tells them the boat left the dock out of Waikiki yesterday afternoon with twelve college kids and two crew on board. When the sailboat did not return, a Coast Guard search was initiated. When the vessel was spotted from the air, all the passengers were gone and there were two dead bodies. Kono spots the vessel. When they get on board, Danny finds the body of the Captain, Steve finds a body of one of the masked men and Kono finds the cell phone. Steve pulls off the mask and says the man looks local. Chin says it could be a group of local pirates, Tongan, who have been all over for attacking charter boats lately. Danny notes that those pirates have been just robbing people, and Chin states that they may have "upped their game". Steve sees the captain had a gun and Steve adds it looks like a firefight. Kono brings the cell phone to Steve and he tells her to enlarge and enhance the video. Steve tells them to tow the boat back and do a full sweep of it. They are about to get off the boat when they hear a banging noise. Steve draws his gun and cautiously opens a storage cabinet to find Susan hiding inside.
On the dock, Susan tells them they were on the boat and then the masked men came out of nowhere. She adds they were just college kids on spring break and hopes they are not dead. Danny asks how she got away, and Susan tells them they were towed to another boat and forced everyone onto it, but one of the kids was hurt and had to be carried on. When that happened, Susan slipped below deck. She feels awful because she was trained to put the passenger first, but she panicked. Danny reassures her that her reaction is completely normal. Steve asks what kind of guns the men who attacked the boat had, and she thinks they were machine guns. Steve shows her pictures of guns and she identifies an AK-47. Susan says she got a glimpse of one of the men when he searched the galley and it was not the guy who was found on deck. Steve assures her they will find the kids.
On land, there are news crews everywhere. Steve tells Chin not to let any news crews release any information that might compromise the case. They see a man running toward them calling Susan's name, and Susan tells them he is her fiancé and runs into his arms. Chin watches this exchange and then looks down to the deck. He thanks Steve and Chin and hugs Susan.
At headquarters, Kono shows them the cell phone footage, but the quality is really bad. She tells them that she pulled the manifest and all the college kids are from the east coast. Some of them went to the same school and flew in together, but none have rap sheets or records of any sort. Danny joins them and says he heard from FBI the kids are still alive and they have indeed been kidnapped. Two hours ago, the parents started receiving ransom demands and the FBI was called, but the governor wants them to solve it as they caught it. The ransom is for twenty million total and they don't care how it is split, just that they get it. Kono notes someone knew these kids came from money and Steve adds it is highly likely the kids were targeted. One of the couples has already landed and Steve says they need to set up a holding area at the Hilton hotel for the families since they will have questions.
One of the parents, the Layton's, play the ransom message for Steve where the kidnapper tells them they have their daughter, Josie and let her speak. They promise to kill her if her parents don't comply with their demands. The girl's father tells Steve she is their little girl and begs him to find her. Steve tells him he will.
At Kapiolani Park, Danny is stretching from pushing Steve's car down the hill. They see Kamekona in a running suit panting heavily. Steve sates, "You're wearing a plastic bag". He sits down and Danny asks when he started jogging and Kamekona tells him he is training for a sumo competition. Steve asks him about the local pirates form the papers and about the college kids. Kamekona tells him about a couple years ago there was a couple from Dubai tied to big money that were kidnapped. Something went wrong at the drop, the couple was killed and there was a local gang, Tongan tied to it. He tells Steve he will make some calls.
At headquarters, Chin shows Kono the pictures of the gunshot victims found on the boat, but their times of death are 24 hours apart. Chin calls the guys and fills them in and Danny says either Max was wrong or they are dealing with a Tongan pirate zombie. Steve interjects it is possible because the Tongan pirate could have been killed a day earlier somewhere else and dumped on the boat. Kono adds they were killed by the same gun. Danny clarifies the Tongan pirate was killed by his own people, but Steve adds he could have been dumped there to frame the Tongans. Steve gets a call from Kamekona who got a tip about a guy named Big Lono who owns a pawnshop in Kalihi that is being used to move the Tongan's stolen merchandise.
Big Lono tells them they are wrong from behind a wire door. On the other side of the door, Danny tells him it is about finding the kidnapped kids. Big Lono tells them he doesn't know anything about it and runs an honest business. Danny asks if it is honest business, he can open the door and they can see he doesn't have any stolen merchandise. Big Lono refuses and when Danny tries to open the door, he tells him it is built to withstand a three hundred pound Samoan meth addict. Danny lets Steve take over and Big Lono tells him the same thing and Steve gives him five seconds to open the door. When he doesn't, Steve tells Danny that he will be back. Danny is disappointed by his calm demeanor and that he walked away. He comes back inside with a grenade. Big Lono doesn't believe it is real and refuses to open the door. Steve lights up the grenade and leaves it on the door and he and Danny run out the door. Big Lono runs away as well as the grenade blows the door off the frame. Outside, Danny yells at Steve for blowing the door off. Inside, they walk through the frame where the door used to be and Danny tells him that this could have been avoided. They find stolen money clip and Steve asks him where they can find the pirates. In Launani Valley, the team enters a house and finding many men, but no hostages. Steve questions, "Where the hell are they?" The hostages are being held in a large cage surrounded by the masked gunman.
At HPD, Kono tells the cop taking the pirate's pictures to get a close up of the eyes for a bi-metric comparison test. Steve and Danny are interrogating a pirate named Saloni about the kidnapped kids, but he does not know anything about them. Danny shows him the picture of the body on the deck and Saloni identifies him as his cousin and asks what happened to him. He tells Steve if he knew who killed him, they would be dead. Saloni tells Steve he robs rich tourists who don't respect the island, but he doesn't hurt them. But he didn't kill his cousin or kidnap the college kids. Steve asks when the last time he saw his cousin was and Saloni said a couple of days ago some folks in town said they had some work for him. Saloni tells Steve to take off his watch stating he took it off a deep sea fishing charter off Molokai yesterday afternoon. That means could not have gotten to Waikiki in time to kidnap the kids. He tells them the watch is engraved, reciting it and adds he robs people, he doesn't hurt them. And he's not about to go down for something he didn't do.
Kono hasn't found any matches between the guys they got and the gunman, so Steve thinks its frame job. Everything the kidnappers needed to know about the pirates was printed in the newspaper; all they had to do was lead them on a wild goose chase. Danny adds whoever kidnapped the kids is smarter than they thought, but not smart enough Steve adds, because they figured it out.
More of the parents have arrived at the Hilton hotel and as the team has joins them in a conference room they are immediately bombarded with questions. Steve identifies himself and gives a statement. A man asks Steve if it is true they have people in custody, but Steve tells them they are not who they are looking for. The same man asks if since they don't know where they are, why can't they just pay the ransom and get their kids back. He introduces himself as Mr. Brown and shows Steve a picture of his son Justin. Steve tries to calm the room down but Mr. Brown insists the pirates are only in it for the money, so why shouldn't the parents use their money to get their kids? Steve tells them he knows what's it like to be on the other end of that call and it is the worst feeling in the world, but giving the kidnappers the ransom is the worst thing they can do.
As they leave the hotel, Kono asks what the real chances of getting the kids back alive are. Steve tells her when his father was kidnapped, he knew from prior experience no matter what move he made, the outcome wouldn't be good, as they rarely are in these situations. But they are going to change that, they are going to get the kids back alive.
At headquarters, Chin has found that Saloni's alibi checks out. Meanwhile, Kono has done a systems check on the kids since they got to the island using their credit cards purchases and phone records. She has found out that none of them paid for the cruise, the tickets were all purchased by one person who paid in cash, but it was not one of the kids. She stated that it was an older man, who wore a hat and sunglasses. Some of the kids stayed at different hotels and ate at different restaurants, but they were all at a club called Storm the afternoon before the kidnapping and have new charges from today.
Kono and Chin go to club Storm where a bunch of college kids are having a good time. They go up to the bar where the bartender cards Kono but not Chin. Kono shows him her badge and asks his name. He introduces himself as Moku and says he and a guy named Bobby have been working the bar. Bobby sees Chin and Kono and takes off. He runs down the escalator, but Kono leaps at him from the other escalator and takes him down with a kick. She brings up the escalator to Chin, who shows him a picture of the kids. Bobby insists he doesn't know anything about the kids and Kono asks why he ran. Kono asks if he took the imprint of their credit cards, ran some charges today keeping the cash. She tells him credit card fraud is only a six-month probation, but kidnapping is life. Bobby insists he had nothing to do with kidnapping the kids. As the police take Bobby away, Chin calls her back to the bar and Moku tells her there was an older guy hanging around the kids. He snuck into the VIP section with some promotional thing, but security ended up kicking him out. Chin asks if the cameras work, and Moku tells him his boss put them in last year to make sure everyone was carded. Kono points out he didn't card Chin, and Chin thanks him for at least not thinking he was Kono's father. Kono asks him for the tape from the day when the kids were in.
At headquarters, Kono brings up one of the security tapes. They see all twelve of the kids having fun along with a guy in a hat that is a little older and matches the gunman's face. First he is at the bar watching the kids, then he approaches them in the VIP section. It is there he gave them passes to the cruise. Chin adds they showed the picture to the tour operator who thinks this is the guy who bought all twelve tickets in cash. Steve figures he put them on the boat to be kidnapped, and Chin adds its smart play, because if you are behind the velvet rope, chances are your parents could afford your ransom. Steve gets a call from a sergeant at HPD who has one of the kidnappers on hold. Steve tells him to put the call through and tells Kono to run a trace. The kidnapper asks what kind of game he thinks he is playing noting that he expected the parents to go to the cops. What he didn't expect him was for him to play with the kid's lives, demanding to know where the rest of the money is. Steve is confused and adds killing people won't get them the money but the kidnapper tells him it is too late for that. Steve asks what he's done and the kidnapper tells him he will call him directly in one hour with new instructions and suggests they be followed exactly. Kono has traced the call to Sand Island as the kidnapper hangs up and tosses the phone on the beach.
Steve and Danny pull up to Sand Island and find it deserted, except for a body in the water. They run to the water's edge and find a boy wearing swim trunks in the sand. Steve and Danny head into the hotel and knock on a door. Mrs. Brown opens the door, stating Justin and when they see Stave & Danny they guess what they are about to tell them. She breaks down and hits her husband and screams it is his fault their son is dead. Mr. Brown goes out into the hall and tells Steve & Danny after they left, most of the parents wanted to do what they said, but Mr. Brown didn't think so. He put $400,000 in a backpack and left it for the kidnappers and thought they would at least let Justin go. When they heard the knock on the door, they thought it was Justin. He just wanted his son back.
At headquarters, Chin has found the bullet in Justin matched the boat captain and the pirate. Kono asks what Steve is going to do when the kidnapper calls. Kono clicks trace as Steve answers the call. He tells the kidnapper that he didn't have to kill Justin, but the kidnapper says he got Steve's attention. He tells Steve he has an hour to get the money or the hostages die. There will be a bus with the kids parked at a location and once the money is delivered, they will go to the airport where there will be a private plane fully fueled. Once they are on the plane the hostages will be released. Steve tells him he never mentioned the plane and needs more time but the kidnapper tells him he does not have it. Steve says okay and the kidnapper tells him the girl from the paper needs to deliver the money. Steve states that she is a civilian but the kidnapper tells him Susan has to deliver the money in order to get the kids back. Steve again asks for more time and the man states, "fifty nine minutes" and hangs up. Kono was not able to trace the call. She asks if he is really going to use Susan and Steve says she is the only one who can do the job.
At headquarters, people are scramble to get the money together and Susan asks why they want her to do it. Steve says the kidnappers saw her in the paper and know she is not a cop. He understands what they are asking of her, but tells her without her, the kids will end up dead. As the phone rings, Susan looks at the people getting the money together and reluctantly agrees to do it. The kidnapper calls, telling Steve to have the money brought to 414 Industrial way and then hangs up.
Danny and Chin have put the wire on Susan and are waiting outside a warehouse. Steve hands her the big duffel bag, telling her she can do it and they will be there if anything goes wrong. Susan struggles to lift the heavy bag and goes inside the warehouse. She walks over to where the kidnappers are. The hostages watch her from inside the bus. She drops the bag in front of one of the kidnappers. The team is watching through an infrared camera. The kidnapper tells Susan that he told her it would work and she smiles. He opens the bag and finds it is full of phone books. Susan hears Steve say through her earpiece, "Did you really think I was just going to let you walk in there with all that money?" The kidnapper demands to know where the money is and Steve presses a button which trigger several flash grenades. The hostages start screaming and the team runs in along with their backup. Steve chases after the main kidnapper who runs through a window. Steve follows suit and chases him onto a trolley where he shoots him. He goes up the aisle of the trolley and pulls off his mask. It is the man Susan identified as her fiancé and the man who bought the tickets for the cruise.
In the warehouse, the hostages are being helped off the bus and Susan is being led away in handcuffs. The sergeant asks Steve how he knew Susan was in on it and Steve explains that the kidnapper called Susan by name when he called. He said it was because he saw her in the paper, but the paper didn't print her name to protect her safety.
At the hotel, the college kids joyfully reunite with their parents as the team watches proudly as the parents hug their kids and one of the moms even hugs Kono.