Rachel Reilly, winner of Big Brother 13, was unveiled as the "mystery houseguest" competing again this summer on season 27.CBS had been teasing a secret player all week and dropping clues on social media as to who it was.

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

Here's what to know about Season 27. What is the theme for this season? The official theme will be "Big Brother: A Summer of Mystery," CBS confirmed this month, according to USA T

Big Brother follows a group of people living together in a house outfitted with more than 100 cameras and 100 microphones, recording their every move 24 hours a day. Each week, someone will be voted out of the house, with the last remaining Houseguest receiving the grand prize of $750,000.

The new season of the hit reality competition series "Big Brother" includes new elements including the introduction of a mysterious masked visitor with a secret accomplice and an unknown houseguest to be revealed sometime during the season.

I'm a Big Brother fan, and like Tucker from BB26, I also "really like puzzles!" Especially crossword puzzles. So naturally, it's my idea of a good time to put together a crossword puzzle that's solely focused on Big Brother (U.S. edition).