TV HIGHLIGHTS

The Flash, 8 PM on Ch. 26:

Barry’s (Grant Gustin) absence means others have stepped up to try to keep Central City safe as the adventure’s fourth season opens with “The Flash Reborn.” However, a particularly lethal enemy wants to reckon with The Flash face-to-face, prompting Cisco (Carlos Valdes) to retrieve Barry from the speed force ... but it’s a different Barry who ultimately returns. Candice Patton, Jesse L. Martin and Danielle Panabaker also star.

2017 BET Hip-Hop Awards, 8 PM on BET; 11 PM on BET:

From Miami, DJ Khaled returns for his second consecutive year to host the iconic music awards, which air live in many markets. In addition to his hosting responsibilities, Khaled also is one of this year’s top nominees, tied with Cardi B and Kendrick Lamar at nine award nods apiece. Nominated for album of the year are “Grateful” (Khaled), “DAMN.” (Lamar), “Future” (Future), “4 Your Eyes Only” (J. Cole), “4:44” (Jay Z) and “Culture” (Migos).

DC’s Legends of Tomorrow, 9 PM on Ch. 26:

Though their disruption of time means Rip Hunter (guest star Arthur Darvill) wants to disband them, the Legends seize the chance to reunite and try to set things right as the fantasyadventure’s Season 3 begins with “Aruba-Con.” They get their first chance immediately as they encounter Julius Caesar (guest star Simon Merrells) in modern times. Brandon Routh, Caity Lotz and Nick Zano continue among the show’s stars.