Big Brother 27,' hosted by Julie Chen Moonves, premieres on Thursday,. See which houseguests are in power as HoH, who is nominated and who has been evicted so far

"Big Brother" Season 27 contestants better grab a life vest, because star Rachel Reilly is checking in as the 17th houseguest

It's also worth noting that when CinemaBlend spoke to Rachel back in 2021, she was eager to play Big Brother again. Fans may remember she wanted to be a part of Season 22's second All-Stars season, but was not able to play because she was pregnant at the time. Now, it would appear she's playing the game again, but for how long is anyone's guess.

"So there's going to be a strong reaction in both directions for this mystery Houseguest."Ahead of season 27, here are the 12 best Big Brother seasons to watch, all of which are available to stream on Paramount+.

Before the season 27 premiere, many fans speculated that the mystery houseguest could be anyone from Celebrity Big Brother UK star JoJo Siwa to a Big Brother newcomer like Tom Sandoval from Vanderpump Rules. Viewers even hypothesized that this season, the host herself, Julie Chen Moonves, would join the cast as a contestant.

Sleeper car bunk room: 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.