May is the busiest month for television, and the action starts early this year. The May sweeps begin Thursday and run through May 21, the official end of the season.

What to expect?

The broadcast networks unveil their fall lineups the week of May 12 and reveal surviving series.

Favorite series present season finales: "Once Upon a Time" delivers a two-hour closer May 11.

"The Blacklist" and "Castle" go May 12. ABC says "a shocking surprise" threatens Castle and Beckett's wedding.

"NCIS," "NCIS: Los Angeles" and "Person of Interest"follow May 13. On "NCIS," Gibbs travels home after his father's death. The episode will be a tribute to the late Ralph Waite, who played Gibbs' father.

"Arrow" and "Nashville" wrap May 14. So does "Criminal Minds," and CBS says a team member clings to life.

The May 15 season finales include "The Big Bang Theory," "Grey's Anatomy" and "Elementary." "Grey's" will say farewell to Cristina Yang. As for "Big Bang," CBS offers this fascinating tease: "With his entire world changing around him, Sheldon (Jim Parsons) considers a major move." What could that be now?

"The Simpsons" and "Family Guy" close up shop May 18, the same night "The Good Wife" ends its best season yet.

Consider this tease from CBS about "The Good Wife": "The futures of Florrick/Agos and Lockhart/Gardner are at stake when the firms consider merging, driving a wedge between Alicia (Julianna Margulies) and Cary (Matt Czuchry). Meanwhile, Diane (Christine Baranski) makes a big decision when Louis Canning (guest star Michael J. Fox) challenges her role at the firm."

"The Mentalist" offers its season finale May 18, and it could be the end. CBS says that Jane will come to terms with his feelings for Lisbon. About time, wouldn't you say?

"Bones" finishes its ninth season May 19, and David Boreanaz directs.

"The Middle" and "Modern Family" exit May 21. "Modern Family" will be focused on the wedding of Mitch and Cam; the two-part finale begins May 14.

"The Middle" filmed its season finale at Walt Disney World, and series fans want to know: How could this happen to the Heck family? Turns out Sue won a trip to Walt Disney World in a Hands on a Hard Body contest. "The Middle" will be a one-hour season finale; the two half-hours are called "Orlando" and "The Wonderful World of Hecks."

Reality series name victors: "The Amazing Race" on May 18, "The Voice" and "Dancing With the Stars" on May 20, and "Survivor" and "American Idol" on May 21.

"Dancing" will present the final performance show May 19; the winner is announced the next night.

"American Idol" used to own the last night of the season. Not this year, as the singing contest's blockbuster status diminished. But the final two singers compete May 20 before the big announcement the next night. CBS hopes "Survivor" cuts into the "Idol" audience.

In other reality news, "Shark Tank" offers a behind-the-scenes special and a new episode May 2. That series' season finale will be May 16, an hour earlier than usual. The show has to get out of Barbara Walters' way (read on).

In special programming, Jack Bauer returns in "24: Live Another Day" May 5 on Fox.

NBC presents a "Rosemary’s Baby" miniseries May 11 and 15. Remaking a classic is a tricky thing to do.

ABC gives retiring Walters a two-hour special, "Her Story," on May 16. Is it really the end for her?

She will get a big sendoff in daytime, too. All the co-hosts in the history of "The View"gather May 15 to honor her. May 16 is her last day at the daytime chatfest. Her final week, May 12-16. The guests during the sweeps month  include Sally Field, Diane Keaton and Neil Patrick Harris.

Andy Samberg hosts the "Saturday Night Live" season finale on May 17.

The Billboard Music Awardswill air May 18 on ABC. Luke Bryan, Imagine Dragons, OneRepublic, Jason Derulo and John Legend will perform.

May is busy, but it can be thrilling. Happy watching!