The team race to find the vigilantes responsible for a number of attacks happening every 27 minutes. Prentiss and Unit Chief Andrew Mendoza head the investigation to identify the perpetrators.
Robin and Ted reminisce about past relationships as they search for a drunken Barney on the day of the wedding; Lily and Marshall come to a resolution; Barney befriends two men who are eager to meet women.
The team tries to free a Marine serving a life sentence, when they find a 50 year old tape from the murder victim.
Wade is faced with a tough decision when Zoe makes a grand gesture; George and Lavon meet their hero, Don Todd (Reggie Hayes); AnnaBeth ponders a future with Davis.
Zoe is happy to help when Wade's father asks for assistance with his love life, but Wade thinks no good will come of it; Lavon ends up in competition with his rival, Mayor Gainey; Lemon's plans for Fancie's seem to go up in flames.