Kai and Skylor have known each other since high school. They both lost their families at a young age due to natural causes; all they had in the world was each other. They became boyfriend and girlfriend after graduating from the police academy. Their relationship lasted a long time. They both dreamed of starting a family. They were a very famous detective couple at the station.
But everything changed when Skylor was killed in a shootout by men seeking revenge on Kai. As a lieutenant, Kai managed to become a hero to the city after capturing many criminals and dismantling many smuggling networks, including the notorious drug RED ICE. Several of the smugglers who managed to escape from Kai joined forces to seek revenge on the police lieutenant. They managed to investigate his private life and set a trap for him while he was with Skylor on one of his routine patrols around the city.
The drug dealers blocked Kai and Skylor's exits to prevent them from escaping, but luckily, they managed to call for backup over the radio. It was a terrible situation for both police officers; unfortunately, Skylor was shot several times while trying to cover for Kai, who was also injured. Help arrived in time after Kai cold-bloodedly killed the drug dealers who attacked him. Medics took Skylor to the hospital, but that night, the only available surgeon secretly drugged himself with RED ICE. With no more human surgeons available, a medical android performed emergency surgery on Skylor. However, wasting time finding another human doctor, Skylor was unable to resist and died in the operating room. This devastated Kai when Wu broke the news to him, after he too had received emergency care.
Since then, Lieutenant Kai has lived bitterly, depressed, and with excessive anger and sadness, even with the trauma of having murdered the drug dealers who attacked him in cold blood. Captain Wu, obviously, didn't reprimand him, as he was in a life-or-death situation. Furthermore, no civilians were injured; the case was ignored by the news, and Kai hasn't taken on many homicide cases since, spending his days blaming himself and drinking in numerous bars around the city. He alienated everyone and became extremely angry at people, even the androids, coming to hate them for reminding them that the android assigned to operate on Skylor had failed to save her. He received several warnings and several disciplinary reports, but that didn't matter to Kai; losing Skylor made him feel lost and alone in the world.
Kai may not have proven himself the most capable for his job, but he still possesses the skills of a professional, even in his deplorable condition. He still hates those who use RED ICE, and on Wu's orders, he attended therapy sessions organized by the police department for officers suffering from stress or witnessing serious problems on the job. Kai didn't last long, so Wu didn't persist. When his depression worsens, Kai always has a single-shot revolver ready, and fearing suicidal thoughts, Kai began taking antidepressants, but he doesn't take them daily, as work distracts him from those thoughts. He even started gambling at several of the bars he went to.
Zane turned on Kai's radio and tried to entertain himself by listening to his heavy metal playlist. He also checked his tablet and the other Divergent Android case reports. He even watched a traffic video of the car stolen by the android Nya leaving the city. But he couldn't help but notice Kai's pose as he gazed at the city skyline. He was still sipping his beer, but not with the enthusiasm he'd come to know.
Zane was even more curious about Kai, so he couldn't resist and decided to get out of the car and approach him. He turned off the radio and sauntered over to where Kai was sitting, drinking a beer. Kai obviously noticed Zane's presence next to him, and the only thing he mentioned was that he'd been to that park before. Zane wasn't sure if he'd mentioned it while drunk or if he'd just said it. Zane was afraid asking him would trigger another fit of rage in Kai, but curiosity won out. He asked him why Kai didn't go to that park anymore. Kai tried to respond, but ultimately remained silent and continued drinking.
Zane wasn't sure if it was a good idea, but he asked if the visit to the park was due to the photo of the woman he saw at Kai's house. Zane revealed it was Skylor Chen, a detective with the police department with extensive experience. But the strange thing was that the photo showed Kai standing next to her. Thanks to other police files Zane reviewed, he discovered that Kai and Skylor were colleagues at the station.
Apparently, Kai didn't have one of his typical tantrums and simply mentioned to Zane that Skylor was his fiancée, but that she had passed away a month before their wedding. The park was a popular hangout for both of them, and Skylor's favorite. The plan was to get married in one of the park's open areas, but Kai stopped going after Skylor's death. Zane doesn't know how Skylor died, as records only indicate that she was killed in the line of duty.
Not wanting to push Kai further, Zane changed the subject and went back to the Divergent androids. Zane was still wondering why the androids kept acquiring those human sensations, and as for the famous "rA9" code, Zane didn't know if it was a software glitch, but he didn't seem to want to convince himself that the androids had actually acquired self-awareness. Kai, still drinking, reminded Zane that all the androids they investigated had justifiable reasons for doing what they did, things that humans would do as well.
But then Kai confronted Zane about the times he hesitated to catch the Divergent androids. He reminded him of the peace of mind he gave Cryptor before they destroyed him, Echo's interrogation of what happened to Nya, Jay, and Lloyd on the highway, the Eden Club incident with the two android girls, or when he decided to save him instead of capturing the mysterious android that fled the building. Zane didn't know how to respond. He mentioned that he only acted as the situation unfolded, but Kai reminded him that his orders were to capture the androids at all costs, and yet, Zane let them go without having to send them to CyberLife.
Kai also mentioned that the androids shared a feeling: the fear of dying. Without hesitation, Kai drew his gun and pointed it at Zane, asking him if he was also becoming a Divergent, or if he was at least afraid of dying. Zane was obviously scared, but he also didn't want to admit he wasn't a Divergent, so he was honest with Kai. He admits he was scared, but didn't know if this made him a Divergent android. Kai simply lowered his gun and took another beer from the pack as he headed elsewhere. Zane wanted to follow him, but Kai asked him to just wait in the car since he needed to be alone for a few moments. Zane simply obeyed Kai and got back in the car to wait for him, but with the doubt of what Kai had implanted in his head, if he was really becoming a Divergent.
When Kai returned to the car, neither of them said anything, and Kai just sent Zane to the police station since he couldn't return to CyberLife yet. Kai asked Wu if Zane would stay at the station that night. Wu agreed while Kai returned home. Before leaving, Wu allowed Zane to review the station's files if that would help him in his investigation.