Big Brother is up to no good in tonight's show, stirring up drama.
In this evening's highlights, the Big Brother housemates awake to find the house has been transformed into a crime ridden city for a Murder Mystery task.
Housemates are each given new identities and costumes, and must solve the murder to complete the task.
Sam and Sarah are brought to the diary room, and find out they have been voted as the murderers in the game via an online public poll.
Brandi and Paul are the detectives in the criminal case team. Their mission is to uncover the killers in the game.
As part of the case, Brandi and Paul visit the deceased victims office. Big Brother has hidden a series of quotes underneath items in the room, spoken by other housemates about Paul and Brandi.
The other housemates watch from the screen in the living room. Paul and Brandi need to decide whether this evidence can help them solve the case.
Following the task, Brandi tries to talk to Sarah and Chad about her response to their comments she found during the task. Both refuse to accept Brandi’s explanation.
Meanwhile, Sam and Sarah are asked by Big Brother to killer nominate two housemates undetected by marking the face of the selected housemates on the video wall. They mark Paul and Brandi.
For the second set of killer nominations, Sarah and Sam must place a horse’s head into the bed of the nominated housemate. They choose Helen and Derek.
If Sarah and Sam pass the task by not being identified as the murderers, the housemates they've nominated will face eviction.
However if they fail, they'll immediately face eviction themselves.
A double eviction will take place on Friday night.