Nick and Hank investigate a series of gruesome crimes on “Grimm.” (Scott Green/NBC )

Few events have been more scrutinized than the minutes leading up to the death of President John F. Kennedy. Narrated by Bill Paxton, “JFK: The Final Hours” (National Geographic at 8 p.m.) takes in-depth and bird’s-eye views of the final day of Kennedy’s life through firsthand accounts.

SERIES FINALE: In the conclusion of the two-part season finale, the two remaining chefs battle it out with a three-course meal before the winner of “MasterChef: Junior” (Fox at 8) is announced.

“Great Performances” takes on “Stephen Sondheim’s ‘Company’ With the New York Philharmonic” (WETA at 9), a staging of the composer’s musical, in which a bachelor, played by Neil Patrick Harris, celebrates his 35th birthday with five married friends. The cast features Stephen Colbert, Jon Cryer, Patti LuPone and Martha Plimpton.

SERIES PREMIERE: From the executive producer of “Jersey Shore,” “The Dirty South” (CMT at 9) follows a group of all-American 20-somethings for a summer on the coast of South Carolina. Although they hail from different parts of the South, they all have one thing in common: southern pride.

Nick and Hank investigate a series of gruesome crimes that may be linked to an old feud on “Grimm” (NBC at 9). Since the zombies have been taken care of for now, Nick continues to recover while Monroe and Rosalee discuss taking their relationship to the next level.

SERIES PREMIERE: “The Lylas” (WE at 9) introduces us to the four sisters of Grammy Award-winning singer-songwriter Bruno Mars, who face a number of personal and professional obstacles once they leave Hawaii and head to Los Angeles to kick off their music career.

RETURNING SHOW: In the Season 6 opener of “Say Yes to the Dress: Atlanta” (TLC at 9), TV personality Adrianna Costa looks for a second, sexier, dress, but her mother hopes she’ll opt for something more conservative.

Grayson becomes curious about Lady Jayne and her intentions on “Dracula” (NBC at 10). He suspects that she could be a vampire hunter for the Order of the Dragon and earns himself a powerful new enemy during his investigation. At the same time, Lucy helps Mina get over a breakup with absinthe, romance and a whirlwind tour of bohemian London.

Journalist Tom Brokaw and actor Rhys Darby come to “The Late Show With David Letterman” (CBS at 11:35), with musical guest Black Joe Lewis.

Actress Mariska Hargitay and Sen. Ted Cruz (R-Tex.) join “The Tonight Show With Jay Leno” (NBC at 11:35), with a musical performance from Gavin DeGraw.

— Rachel Lubitz