A school holds a academic quiz in the high-school auditorium. A teenager named Pierce gets many of the answers correct. His mom, Dr. Higgins smiles with every correct answer -- and frowns at the rare incorrect response. Afterward, the competitors head home. Brandon, Pierce's main rival, is soon tackled and killed by a snarling, lion-looking wesen.
Back at Nick's, the off-duty detective zips up Juliette's cocktail dress. It appears that they're learning how to be a couple again. The pair heads to a police department banquet where Renard is receiving an award. Juliette looks strangely at the captain, who stares back. Nick and Hank then get a call about a murder. They're officially back on duty. Renard volunteers to give Juliette a ride home. She doesn't look entirely comfortable with the idea, but agrees.
At the scene of Brandon's murder, Nick finds a cell phone. It rings -- and Nick answers. It's one of his teammates, a teenage girl named Jenny. Renard then drops off Juliette, but doesn't drive away. He watches her from his parked car before using Nick's hidden key to let himself inside as Juliette enters the shower. When Juliette exits the shower, she notices that a picture of her and Nick has been shattered. Cut to Renard, whose face begins to morph into something terrible as he speeds away from the house in his car, shaken.
The next morning, Nick and Hank interview Pierce and Jenny, who explain that they last saw Brandon at quiz practice. "Do you have any idea who might have done this?" Dr. Higgins asks. Not at the moment -- no. The quiz coach, Don, shows up and tells the detectives that he knew Brandon since first grade and threatens to hurt whoever killed his best student. Don then reveals himself to be a Wesen, though not the same one that took out poor Brandon.
Nick and Hank don't know that, however -- and later discover that Don has a history of aggressive behavior, resulting in a restraining order years ago. Hank wonders if one of the other students did the deed as the pressure to win the academic quiz was tremendous. Scholarships are on the line. Nick and Hank are then introduced to an intern Ryan, who claims to idolize them. Ryan is so flustered at meeting his heroes that he trips over a wastebasket.
Eric, Renard's brother, then meets Adalind at a bar. "Have we met before?" Eric asks. Adalind reveals that she knows Eric is trying to restore his family to power. Adalind mentions that she knows Eric's brother. "The circumstances of our discord were quite ... Grimm," she comments. Eric smiles. Later, Renard enters Rosalee's shop, which is still being run by Monroe. Renard requests a potion for obsessive behavior, but becomes nervous when Monroe seems to recognize him. Renard says he'll come back tomorrow to get his order.
Jenny then calls Pierce and agrees to meet him at the bleachers of the high-school football stadium. When Jenny arrives, she is attacked by a growling wesen. Sometime later, Nick and Hank arrive on the scene. Jenny has been massacred. They find a watch under Jenny with an engraving to Pierce from his loving mother. The detectives then head to Pierce's house and question him about the watch. "Have you been with Pierce all day?" Nick asks Dr. Higgins. Pierce and his mother get stressed out and morph into lizard wesens.
After Nick and Hank leave, Pierce goes inside to find what appears to be a very bloody garment in the washing machine. Don then calls and tells Dr. Higgins that he's pulling the school from the academic decathlon. When Pierce hears, he is furious. Nick does research and discovers that the lizard wesens are nonviolent creatures incapable of murder. So Nick and Hank head to Don's house and find the man's dead body. His throat has been slashed.
Eric and Adalind have drinks. Eric explains that one of his father's mistresses was revealed to be a hexenbiest. So Renard's mother was put on the family jet and whisked away to the United States. Adalind says that they have a lot in common: Renard and the Grimm. Pierce then calls Nick. "I think I know who killed Brandon," the boy says before Dr. Higgins forces him to hang up. Pierce then runs to the laundry room and discovers that the bloody clothes were his. Pierce then morphs into a lion creature and attacks his mother.
Nick enters is tackled by the teen wesen. A furious fight ensues and, eventually, Pierce is subdued. Dr. Higgins explains that her boy is two kinds of wesens. "I made him that way before he was even born," she cries. "I altered his DNA." Pierce has no idea and killed his friends unknowingly when he saw them as a threat. Hank then notices that Pierce has escaped. Nick gives chase to nearby water tower. Pierce threatens to jump and Nick tries to talk him down. "You didn't even know what was happening!" Nick says as the boy morphs from harmless lizard to murderous lion. The boy tries to jump and Nick grabs his arm, handcuffs him and pulls him to safety. Pierce is heading to prison.
Renard returns to Rosalee's shop and is given a potion that will dampen his obsessive behavior -- but not eradicate it. "A condition like yours left untreated can be downright dangerous," Monroe explains. "Going with the flow is really not a healthy game plan." Renard seems to take the advice to heart.