Tonights task to win a "very special reward".
The remaining six housemates are to have their nerves tested with the fifth Saturday Challenge - they must draw straws.
The lucky housemates who pick the long straws live on TV at 9pm will win a "very special reward".
Those housemates who draw the short straws will be denied access to the reward room.
The housemates will be given a straw holder with six straws in it and each have one chance to draw a straw from the holder.
They will have just one minute to decide on the order in which they will draw straws and relay this information to Big Brother. Big Brother will then signal each housemate to draw their straw in turn.
The order in which the straws are drawn also dictates the order in which the winning housemates will enter the reward room. The first housemate to draw a long straw will be the first housemate to enter the reward room and so on.
Once in the reward room, housemates may not leave until instructed by Big Brother. They are also not permitted to communicate with housemates still in the house.
Story from Ananova