'Big Brother' Season 25 Kicks Off With Wild 1st Competition, Chaos and Surprise 17th Houseguest! (Recap)

This season's new houseguests got right down to the gameplay on Wednesday's big premiere.

Big Brother kicked off a new season on Wednesday, and host Julie Chen Moonves had some big twists and turns for the 16 new houseguests who moved into the Big Brother household -- including a mysterious 17th houseguest that wasn't revealed until the closing moments of the night and shook things up in a big way for both contestants and fans alike.

The show began by introducing the new houseguests -- eight at a time, instead of just four, like usual -- and introduced them to the very narrative-driven new Big Brother Multiverse house theme.

(The Big Brother Multiverse is kind of complicated but revolves around three previous Big Brother contestants breaking in and causing a rift in space and time that is reflected in the design of the house. Check out our exclusive house tour for a better, more in-depth explanation.)

After getting a chance to meet each other, the guests were then instructed to enter the house and head right to the backyard to compete in a series of different challenges -- each based on a different "universe" from the house. The houseguests were divided up, four to a group, between the four challenges.

However, before the competition could commence, Julie dropped the first unexpected bomb of the season. This wasn't a Head Of Household competition like it usually would be in seasons past. Instead, the groups were competing to stay off the chopping block.

To really shake things up, the first comp of the season was a nomination comp, meaning whoever came in last in each of the four groups would be in danger of getting evicted.

The first competition -- courtesy of the "Scramble-verse" -- required four houseguests to disassemble a block structure and reassemble it inside a box across the courtyard as quickly as possible. Despite his best efforts, Jared Fields was the last to solve the puzzle and the first guest of the season to land on the chopping block.

The second competition -- from the "Humili-verse" -- challenged four houseguests to essentially use a rowing machine that caused a giant boot to kick them in the butt every time they pushed the handles. The last house guest to kick their own butt with the giant boot 100 times would be the loser. Once again, Big Brother proves to be one of the weirdest performance art experiments in TV history. Ultimately, Kirsten Elwin (a molecular biologist and swimwear startup entrepreneur) came up short.

The third challenge -- from the "Comic-verse" -- saw four houseguests trying to correctly arm a "goo bomb" that would explode in colored goo all over them. The last houseguest to get goo'd lost. That dubious honor went to Felicia Cannon.

Finally, the last competition -- from the "Scary-verse" -- saw the remaining four houseguests hold on for dear life while laying on the floor in front of a creepy portal to a dark and foreboding dimension and a giant demonic monster hand tried to drag them into the "nether region," as host Julie Chen Moonves insisted on calling it, repeatedly.

After an agonizingly long stretch of live TV that felt like no one had properly play-tested, Cory Wurtenberger was the first to lose his grip. While that technically means he's nominated for eviction as well, he was also dragged off into the "nether region" and wasn't seen again for the rest of the episode. Which is admittedly unsettling.

As the dust settled on the first weird, complicated competition of the season, Julie had one last big reveal that might truly change the game up in a big way -- a 17th houseguest who hadn't been previously announced.

So who was added to the game in a surprising and bizarre twist? Survivor icon Cirie Fields -- who also happens to be the mother of Jared Fields -- the first houseguest to get nominated after not finishing his weird puzzle block challenge.

This is the first time a Survivor contestant has competed on Big Brother. And Cirie isn't just any Survivor alum. She's competed on four different seasons and is considered by many fans to be one of the greatest players to never actually win -- very similar to the three returning Big Brother contestants who will apparently come into play at some point later in the season.

Big Brother returns Sunday night for the first real Head of Household competition. Big Brother airs Wednesdays and Thursdays at 8 p.m. ET/PT and Sundays at 9 p.m. ET/PT on CBS.