Pretty Little Liars (8pm, ABC Family) - The girls try to corner "A" at their school's hoedown and Hanna is stalked by a classmate who has an explosive secret.
Whose Line Is It Anyway? (8pm, CW) - Keegan Michael-Key ("Key and Peele") appears.
Nine for IX: The '99ers (8pm, ESPN) - This documentary, directed by Erin Leyden, looks at the 1999 U.S. Women's World Cup champions and the event's lasting impact on soccer and women's sports. Mia Hamm, Kritine Lilly, Carla Overbeck, Brandi Chastain, Briana Scurry and producer Julie Foudy are featured.
Who Do You Think You Are? (9pm, TLC) - Actor Chris O'Donnell explores his father's side of the family and its patriotic legacy.
Rizzoli & Isles (9pm, TNT) - Jane and Maura are enlisted to make a presentation about the case of serial killer Charles Hoyt at a law-enforcement symposium. While looking back at the Hoyt murders, the duo make a chilling discovery and must face off against a new serial killer.
Drunk History (10pm, Comedy Central) - Events in Nashville include Lewis & Clark's dangerous journey and Dolly Parton saying goodbye to the man who made her famous. Guest reenactors include Tony Hale, Aubrey Plaza and Jack McBrayer.
Suits (10pm, USA) - Cameron's dirty tactics on Ava's case lead Harvey to recall why he left the D.A.'s office. Elsewhere, while Rachel visits law schools, Mike looks back at what prevented him from earning a degree.