Big Brother” unveiled its “All-Stars” cast during Wednesday night’s two-hour live premiere. For the first time in its 20-year history, the show aired the live move-in of 16 returning houseguests from previous seasons.

Host Julie Chen Moonves greeted the cast in groups of four and explained the safety precautions they took to resume production. The cast kept their masks on and maintained a 12-feet distance from the unmasked host.

“All of this season’s houseguests have been individually quarantined for the past two weeks,” said Chen Moonves. “You’ve all been tested multiple times for COVID-19, as have I, and you are all clear to play this game.”

The cast immediately took their masks off upon entering the house, to compete in their first competition. They searched the set for a specific item displayed on the TV screen and solved a puzzle to secure a spot to participate in the next competition.

Only six of the 16 returnees — Memphis Garrett, Cody Calafiore, Christmas Abbott, Kevin Campbell, Nicole Franzel and Ian Terry — qualified to compete for Head of Household, the high-stakes position safe from eviction and in charge of nominating two houseguests for elimination. They raced across star-shaped platforms to beat the clock as Nickson won the title with a 22-second record. Garrett came in second.

The losing contestants were asked to pick a mystery envelope at the end of the race. Among them, Abbott was awarded a $5,000 cash prize.

Chen Moonves also teased the cast that this season will feature a new twist: the safety suite. More details on the new rooms will be revealed Sunday.

Other returning houseguests include Daniele Donato, Da’Vonne Rogers, Tyler Crispen, Enzo Palumbo, Janelle Pierzina, Bayleigh Dayton, Nicole Anthony, Keesha Smith, Kaysar Ridha and David Alexander.

Last Thursday, CBS announced the show will debut its 22nd season with an “All-Stars” cast, including former winners and fan-favorites. Following tonight’s season premiere, the series will air weekly episodes on Wednesdays and Sundays and live evictions, hosted by Chen Moonves, on Thursdays.

This summer marks Big Brother’s 20th anniversary since it debuted on CBS in July 2000. This is the second “All-Stars” season in the series’ history, the first time being in 2006.