'Alert: Missing Persons Unit', also known as 'Alert,' revolves around the reappearance of Jason Grant and Nikki Batista's son Keith after he was kidnapped six years ago. Keith's sister Sidney becomes convinced that the boy is not Nikki and Jason's son since she has unintentionally killed him. However, the ninth and tenth episodes of the show reveal the mystery behind him.
Is the boy really Keith?Who is Lucas?
No, the boy isn't Keith. He is Lucas, an imposter who claims to be Keith. Following the misunderstanding that one of their kidnapping victims is their son, Jason and Nikki arrest Beth Colt, who claims to be the person who killed them. A woman arrives at the scene and abducts Keith. The two police officers rush to Beth to seek any information regarding the kidnapper, only for her to reveal that she has never seen the boy.
Sidney reads the boy's diary to see if she can offer a clue to his parents to her missing brother, only to discover references of an unknown woman named "EH." Nikki and Jason discover the supposed Keith, who later tells Evelyn and Lucas that the missing boy was Lucas.
Evelyn realized that she would be able to kidnap Lucas and demand a ransom. He eliminated newspaper reports and ensured that he didn't miss any interviews with the family so he can discover even the minor details about Keith's likes and dislikes, his tense relationship with Sidney, and more.
Lucas felt worthless when he realized that his mother was willing to sell him for money. That was when he began to notice two parents who would go to any lengths or efforts to get him back in Nikki and Jason. It was there that he began to yearn for the love and care they offered him.
Lucas may have been surprised by Sidney's assertion that he is not her brother since Keith has died. Eventually, he anticipates her suspicion about his identity influencing Nikki and Jason, which leads him to replace a lock of Keith's hair with his hair. Meantime, Evelyn starts to harass him for the money she planned to extort from Nikki and Jason.
Lucas realizes that he cannot continue to be ambiguous. He understands that he needs to incriminate someone as his kidnapper so that Nikki and Jason may complete the investigation without any further delay. This is when he discovers that his best friend Oliver was a victim of Beth Colt.
If Lucas had not abducted him to confront him about the money, he would have done the right thing by pretending to be Keith, since, in his opinion, Nikki and Jason would spend a few days with their son again.