Reid tells Prentiss about Lindsey Vaughn being his mother's new nurse and asks her to find her mother. Her original nurse Cassie is missing, and Walker and JJ don't find her or Diana at Reid's apartment.All the prisoners Reid poisoned got released from the infirmary. Lindsey has been living in Reid's building under another name.
They find Cassie dead in Lindsey's apartment, as well as surveillance photos of Reid. Reid creates a shiv from a toothbrush.Kevin Cho from Witness Protection sets up a meeting for BAU with Jack Vaughn. Prentiss tries to get Reid moved into protective custody, but the warden refuses.
Lindsey has used her father's gun to rack up 15 murders over five years. Jack said Lindsey had called him two months ago, asking about drugs in Mexico. Emily tries to go through a judge to get Reid in protective custody.
While talking to Shaw, Reid stabs himself in the leg with the shiv, which gets Shaw in trouble and him thrown into solitary. Garcia gives Prentiss a letter of resignation and says if Reid dies, she quits.The team works all night to create an airtight case for Prentiss to present to the judge.
A manila envelope is slipped under Reid's door, containing a threatening note from Shaw. Prentiss gets the judge to approve Reid's release. Alvez is threatening to get Shaw transferred to a Michigan prison where he would be in danger if he doesn't forget about Reid.
Reid discovers that Diana's scrapbook has been rearranged. Cat Adams is behind Reid's imprisonment and Diana's abduction, not Mr. Scratch. Reid and JJ go to visit Cat in prison, even though everyone has doubts about Reid confronting her.