CBS announced late Wednesday that unbeknownst to the remaining houseguests, Big Brother 6 will feature a double eviction this week.

As usual, one of this week's two current eviction nominees (Janelle Pierzina or recent returnee Kaysar Ridha ) will be evicted during tonight's live Thursday evening Big Brother 6 broadcast.

However, once tonight's eviction is announced and the live competition that will determine the Head of Household completed, Big Brother hostess Julie Chen will immediately call the new Head of Household into the private diary room and inform him or her that they must immediately nominate two houseguests for eviction.

Then, after gathering the other houseguests in the living room and informing them of the sudden twist -- a twist that CBS is billing as this season's "first" double eviction -- the new Head of Household will immediately announce their nominations live on the air.

CBS will broadcast the second eviction as part Big Brother 6's broadcast on Saturday, August 20. After their eviction, the surprise second evictee will become the first member of the Big Brother 6 jury.

Last year's Big Brother 5 also featured a similar double eviction twist, however unlike this season, the double eviction occurred when only six houseguests remained. Drew Daniel won Big Brother 5's ninth Head Of Household competition, after which Julie surprised the houseguests with the announcement that Drew's reign would last only 48 hours and end with the eviction of another houseguest.

Two days later, CBS broadcast a special jam-packed live Big Brother 5 Saturday broadcast in which Drew announced his two nominees, the Power of Veto competition and ceremony were held, a ninth houseguest (Marvin Latimer) was evicted, and a tenth Head of Household competition was conducted.

CBS has not revealed whether this week's special Saturday eviction broadcast will feature a similar format.

Last year's special double eviction was believed to have resulted from the fact that secret twin partner Natalie Carroll had managed to successfully avoid detection and enter the competition as an individual player. With Big Brother 5's finale date having already been locked in, Natalie's surprise midseries addition had resulted in one too many Big Brother houseguests remaining in the house.

CBS has previously announced that Big Brother 6's finale will air on Tuesday, September 20. Given that after tonight, a maximum of only four possible Thursday broadcasts will remain (Survivor: Guatemala will premiere in Big Brother's regular time period on Thursday, September 15, although CBS is expected to still air Big Brother later in the evening) while after Saturday's eviction, eight houseguests will still remain, more surprise evictions would appear likely.