Cameron and Kirsten bask in the afterglow while she worries about her mother. Camille and Amanda decide to move in together. Ivy reaches out to Linus, but he's not interested in talking to her. When he finally does agree to see her, she admits she hacked his email. He walks away.
At the lab, the team is surprised to find Admiral Decker waiting for them along with a new victim. Except 84-year-old Denise Nichols was not murdered. She died in her sleep beside a hidden metal room they cannot access. She's the one who picked the stitch cases. When the stitch begins, Kirsten has trouble seeing due to the high oxytocin levels. Linus did not account for an elderly subject. Maggie is furious with Kirsten and Cameron.
Kirsten and Fisher go to Denise's house and Kirsten is able to access the secret room. The team pieces things together and figure out she was a former NASA employee. They believe she plotted a trajectory for them to follow to Kirsten's mom. When Kirsten and Cameron arrive at the facility, Stinger and Ivy are waiting for them. But Ivy didn't come alone. Maggie and Fisher are waiting. Their plan was to lure Stinger into the open.
As they trade gunfire, Jacqueline's pod is damaged. Kirsten needs to stitch into her to try to wake her up. They're worried because they've never stitched into a live person. But Stinger has. He agrees to give direction. Cameron is uncertain, but follows through because it's what Kirsten wants. When the stitch doesn't work, Stinger and Cameron come to blows. Stinger was making a point that Kirsten and Jacqueline need to switch places.
The team realizes that they've been connected the entire time due to nanobots Stinger implanted in each of their brains. Kirsten was the one really picking the stitches. Denise only read the data. Cameron confesses his love to Kirsten as he puts her in the tank and is forced to lower her body temperature until she's at the same level a corpse would be. He helps her through it; tells her to channel all her love into her mother. She does. Jacqueline wakes up and Cameron revives Kirsten.
Maggie tells the team that Cameron's mother has examined Kirsten and there's a problem. Her memory was affected and she doesn't remember the stitching program or Cameron. He's devastated and furious with himself for causing this. Kirsten introduces herself to him and remembers meeting him as a kid. She tells him that his heart will get better soon. Cameron walks away and Kirsten's expression hardens when she turns to an unseen person and says she'll never forgive that person for making her do this to Cameron.