Sarah's cover is blown by a face from her Dark and Troubled Past: Heather Chandler, her high school bully. Her attempts to keep a curious Chuck away from her past are complicated when he flashes on Heather's husband, engineer Mark Ratner. He's suspected of selling military secrets, so Sarah is forced to go undercover with Chuck in tow, as herself: Jenny Burton.
It soon becomes clear that Mark is being forced to sell to the Russian mob, who have threatened to kill Heather if he doesn't. He's more than happy to make a deal, and sets up a meeting for the next day. Which just happens to be his, Heather's and "Jenny's" high school reunion.
The team head to the reunion, where Chuck is stunned to learn that Sarah was once quite the ugly duckling. Chuck and Casey (mostly Casey) manage to keep Mark safe while Sarah goes after the true mastermind of the treason plot... Heather. After winning a brutal fight against her high school bully, Sarah emerges back onto the dance floor just in time to be crowned Reunion Queen.
Trope Flash:
- Alpha Bitch: Heather Chandler could give the Mean Girls a run for their money. A former cheerleader who enjoyed tormenting the less popular, she later married the nerd she once jeered at for materialistic reasons while treating him like crap and now enjoys selling military secrets to the Russian mob.
- Class Reunion: The climax takes place at Sarah's ten-year high school reunion. It's pretty therapeutic for her, as she gets to knock out two of her former bullies and is crowned Reunion Queen.
- Dark and Troubled Past: We finally learn a little about Sarah's life pre-CIA. Her name was Jenny Burton, and her father, a conman, was arrested when she was in high school. She was recruited by CIA Director Graham right after. However, it also turns out that she went by various names while travelling with her father, so her true name remains a mystery.
- Gold Digger: Heather states openly that she married nerdy Mark Ratner for his money, but he wasn't ambitious enough for her. So she came up with a plan to sell his designs to the Russian mob while framing him.
- Mistaken for Badass: Various circumstances lead Mark Ratner to think Chuck is a badass agent capable of taking on multiple Russian gangsters. The first time, he's shut in a toilet cubicle and misses the action, only emerging once Casey has finished Curbstomping the gangsters, leaving only Chuck. The second time, he's trapped in a locker.
- Red Herring: The reunion mission is complicated when Chuck flashes on a skeevy ex-jock's tattoo. Sarah and Casey apprehend him, only to find he's a low-level drug dealer. Meanwhile, the real mobsters are homing in on Chuck and Mark.
- She Is All Grown Up: Many of Sarah/Jenny's high school classmates are stunned when they see how beautiful the
Hollywood Homely girl they knew has become. After her big fight with Heather, she's crowned Reunion Queen. - Title Drop: The Cougars were Sarah's high school football team. The trope plays pretty literally when Sarah wins her fight with Heather by knocking a cougar-shaped trophy onto her head.Sarah: Go Cougars.
