While out at the movies with his friends, teen Greg Lux logs in to his family's home security cameras to see that his father, Mike, has been murdered. The new Chief Medical Examiner, that would be Curtis, hears a vibrating cell phone at the crime scene. It's coming from Greg's mom, Robin, who is found bound and gagged upstairs. Megan quickly determines that she's dead, too.
Mike Lux's business partner, Owen Kreger, wonders why his friend just didn't open his safe during this apparent robbery. Megan notices that Robin Lux's injuries aren't as severe as her husband's. She believes the killer knew and cared for her. Physical evidence suggests that Owen Kreger may have been involved. While it's true that Kreger was secretly in love with Robin, he's no killer.
Bud notices a business card for a plumber who had worked at places targeted in two other home invasions. This lead doesn't pan out, but another one arises. Megan realizes that Greg isn't an only child. He has a brother, Aaron, who took off four years ago. Not even Greg's best friend, Travis, knew about this. That's because Mike Lux wanted to erase all memory of his first born son. Bud and Sam arrest Aaron as he tries to pawn some of his mom's jewelry. Looks like there's a new prime suspect in town.
Aaron says his father used to beat him relentlessly. He left home, but kept in touch with his mom. She gave him her jewelry for money so that his father wouldn't find out. The guy ran a very strict household. Aaron wished his dad dead many times, but he didn't kill him. His only regret in all this is that he left Greg behind. Curtis realizes why once he sees all the bruises on Greg's body. He promises to help the boy.
Greg has the same kind of rash that was found on his mom. They are both allergic to a substance that's used to treat dents on cars. Greg's friend, Travis, has such a product as well as knife with a blade that matches the one used to kill Mike Lux. Travis had also been a victim of abuse. He did what he had to do save his friend. Travis never meant to hurt Robin. Her death was accidental. Case closed.
Curtis made a promise to Greg that he would try to help him. That's why he reunites him with Aaron, who promises that he will never leave him again. They can be a family now. It's what their mom would have wanted. Kate is impressed at how Curtis handled the case, so she admits to being the prankster who filled his office with inflated surgical gloves. It was just a little reminder to not let this job go to his head.
Megan's relationship with Aiden is moving along nicely, though he thinks she may be afraid of something. He's right. Megan admits that she's scared of being vulnerable. Aiden convinces her that their relationship could work if she's willing to give it a try. Megan's happy nod assures him that she is.
Lacey has a crush on a 16-year-old boy named Tyler. He's really cool. He drives and has a band. Unfortunately, Megan learns that this cool boy has a cool girlfriend. Lacey is heartbroken when she finds out. Fortunately, her mom is there to comfort her. Megan even props Lacey's all-time favorite stuffed animal under her chin as she gently strokes her daughter's hair. Nice.