As the episode began, a man was relaxing by the pool of a very nice mansion with an ocean view. He got a call and promptly left, getting into a truck with the words “Dr. Pool Spa” on the driver’s door. He was a pool man. When he arrived at the location of the call, he was cleaning the pool, then opened the door to go inside. He was shot and killed. When the team arrived on the scene, Kono told McGarrett the pool guy’s name was Nico and that he was trusted with everything in and around the house, which had been empty for a month. The only other person who had access was a family friend who checked on the house – a sophomore at Waikiki Community College. Then, Kono took McGarrett inside and showed him a room full of air fresheners hanging from the ceiling – hundreds of them. An HPD officer took Kono outside to the trash, where she called McGarrett. Together, they found a bottle of acetone. McGarrett surmised someone had been making crystal meth. When he went to find Dawn Hatfield, the family friend, she told him she forgot to re-set the alarm on her last visit. Back at HQ, Chin told McGarrett all prints were wiped clean at the house. However, the wireless modem had been logged into recently by a Joseph Son, a chemistry major at Pacific Isle University. When McGarrett went to arrest Son, he ran and ended up committing suicide by leaping backwards off a building. There was nothing to connect Son at his apartment to anything related to the house of the murder of the pool man, but the lab found that the bottles from the trash also contained other chemicals that revealed it to be used in the making of a bomb, not a meth lab. McGarrett asked for Grover’s help. Kono examined Sun’s laptop and found communications between him and an Al Qaeda leader in Yemen named Muhammed Nazaria, a poster boy for the American Jihad Movement. Kono showed two of these messages to McGarrett. Chin found that Sun had been to Yemen twice in the last 18 months with a Brian Miller. The team went to pick up Brian Miller, but he put up a fight and was shot and killed. There was another unexpected shooter at the house – Dawn Hatfield. The team took her in for questioning but got nothing from her. Evidence at the scene suggested the three young people planned to attack Hickam Air Force Base. Chin sent some of this evidence via scan to a contact at the FBI HQ, Terrorist Explosive Devices Analytical Center at Quantico. Evidence from the FBI pointed to at least two bombing incidences. One of them was in Afghanistan, where a convoy of five marines was attacked in 2012. There was only one survivor, Kirk Emerson, who lost both legs and an arm in the attack. He was recovering at the VA Hospital in San Diego. The FBI’s database also revealed that two Afghan Nationals were in the country as legal refugees and lived only a couple of miles from base. The two Nationals were located and taken into custody. At the end of the episode, Danny and McGarrett went to San Diego to find a tearfully grateful Emerson and tell him in person that they had arrested the Afghan Nationals that had attacked his convoy.