The Stitchers team is on the defense when Cameron and Detective Fisher are targeted in a shooting. Kirsten's stitch leads them to Robert Barbiero, a security expert who has worked with Maggie in the past and was close to Kirsten's mom. As Kirsten follows the clues that Ed Clark left her, she finds unexpected answers to long-held questions.

Fueled by his love for Kirsten, Cameron finds a way to bring her back to reality, but it could cost them their relationship. Meanwhile, the Stitchers lab is on lockdown, leaving an anxious Linus unable to check on his father’s condition after surgery. But, as the team prepares to be reassigned for breaking protocol, NSA Director Mitchell Blair surprises everyone by demanding an emergency stitch that yields shocking new information.

Cameron’s estranged father, currently serving time in prison for white-collar crimes, is accused of murdering a prison guard. Going against protocol, Kirsten stitches into the guard’s memory for clues.

A series of murders, including a professional volleyball player, lead the Stitchers team searching the darkest corners of the Internet. Meanwhile, Kirsten gives Maggie an ultimatum.

Kirsten’s father Daniel Stinger shows up and Kirsten must perform the most important stitch of her life.