Behind a secret entrance, this train-themed bedroom straight out of a murder mystery novel contains bunkbeds for six Houseguests (the first time the BB house has had bunk beds since season one!) and a sleek Art Deco design.

"Big Brother" is promising a summer of mystery when Season 27 premieres next week, as seen by CBS's new first-look images of the updated house theme — aka, Hotel Mystère. "Houseguests will enter the enigmatic Hotel Mystère,

Big Brother 27 has revealed its theme and the house's interior ahead of its July 7 premiere. According to a CBS press release, Big Brother season 27 has a mystery theme, which will be called "Big Brother: A Summer of Mystery.