CBS is set to premiere the 27th season of its long-running reality television show "Big Brother" on July 10, 2025, at 8 p.m. ET. This season, titled "Big Brother: A Summer of Mystery," features a new theme centered around a mysterious hotel called "Hotel Mystère," described as an enigmatic yet luxurious version of the traditional "Big Brother" house. The season will introduce 16 new houseguests, including a dungeon master, a professional bull rider, an aura painter, an attorney, and an AI consultant from Sarasota, competing for a $750,000 grand prize. Additionally, the season will feature a 17th mystery houseguest whose identity remains undisclosed, adding an element of intrigue to the competition. The season will also include new twists such as a masked visitor and a secret accomplice, along with a new iteration of the BB AI Arena. The show continues to be a staple of CBS's summer programming, maintaining its status as one of television's longest-running entertainment series.