After her support group meeting, another member approaches Kitty for help. Her daughter, Tess, is missing and asks Kitty to find her
Bell and Sherlock are at a crime scene. An elderly couple both died in bed at the same time. Sherlock says they are a casualty of another crime committed elsewhere in the building.
Someone burned rubber in the basement which emitted a toxic gas. Sherlock finds a burned body with a tire around his neck.
Clay Dubrovensky was the second floor tenant who worked for the SDS Cartel, growing marijuana for them.
Kitty gives Sherlock an update on her case, then asks if he spoke with Watson.
Watson wakes up to Sherlock making her a smoothie. He asks Watson what she wanted to tell him yesterday. She is closing her PI business and going to work with Leda, an insurance company, as an investigator. She will remain a police consultant.
Gregson calls them to the growing house. The marijuana plants are dying, which Watson and Sherlock find strange. If the cartel had killed Clay, they would taken care of the plants. Sherlock discovers a rare and valuable orchid in the greenhouse.
Sherlock no longer believes the SDS Cartel killed Clay. Sherlock thinks that Clay may have bought and sold the flower in an auction.
Sherlock and Watson meet with Barbara Conway from AgriNext. She bought the orchid from Clay and Sherlock accuses her of killing him when he didn't give it to her. She shows them her plant. There are two orchids.
Sherlock examines both plants and realizes Clay cloned the orchid.
Sherlock congratulates Watson on her new position and says he is making changes too. Before he can share his news, Gregson calls. There were two more murders by a burning tire necklace, including one right in front of AgriNext.
Sherlock notes the rope was different from the rope used in Clay's murder. They speak again with Barbara Conway. She admits that AgriNext offered Clay a job and was trying to buy out his relationship with SDS.
Tess finds Kitty. The man in the jaguar was her mother's rapist and her father. Tess was hiding to try to get him into trouble.
Sherlock tells Watson that he wants to make Kitty his partner.
The police arrest the SDS member guilty of the AgriNext murders. He denies killing Clay.
Watson meets with Clay's ex-girlfriend. She needed to get plant food from his apartment. He apparently gave all of his girlfriend's a special plant.
Barbara Conway meets with Watson. She starts in about who might have killed Clay and Watson interrupts her. Tells her that she knows that she killed Clay because he was seeing his ex-girlfriend again.
Sherlock gets a call from Gregson to come alone to a murder scene. The dead woman has the same markings on her back that Kitty had after her kidnapping.