HOUSEMATES face a double eviction on Friday after Big Brother revealed the most mysterious task in show history.
The White Room challenge will see three housemates attempt to win a pass to the final and £25,000 of the prize fund.
But we can reveal the task could also see an extra contestant booted out on eviction night.
A show insider said: “Only a select few behind the scenes know what is in store for the housemates in the White Room.
“But one thing is for sure – it’s going to shake up the house more than any other task this series.
“It could even end with someone getting evicted, meaning the house could be a very different place by next weekend.
“They’re all desperate to make the final so a double eviction will cause a massive amount of drama.”
Viewers can see the action in a 90-minute live episode on Wednesday night.
Meanwhile, the wannabes were yesterday competing to win luxury prizes in an endurance test.
Housemates had to stand on giant presents for the longest time, without knowing what they would win.
Our insider said: “Prizes range from a holiday in Barcelona to a toilet brush.
“If any of them wait all day and win the brush it’s not going to improve the mood.”
Find out who won at 9pm tonight on Channel 5.