The second set of this week's killer nominations have been revealed on Celebrity Big Brother 2017.
Helen Lederer and Derek Acorah have been put up for eviction, joining Paul Danan and Brandi Glanville in facing eviction this week - at least as things stand.
Sarah Harding and Sam Thompson were voted for by the public to take part in the new twist, where they stand to gain immunity but also risk eviction.
They have to get away with 'murder' by killer nominating other housemates without being caught.
In the house yesterday, Big Brother gathered the group to begin a murder mystery task: "Housemates there has been a murder and the victim is none other than the infamously famous celebrity agent Stella Star.
"Shortly, Big Brother will call all suspects to the Diary Room individually. At least 2 of you will be told that you are the killers.
"Over the next 2 days, more of you will fall victim. Housemates, these cut-throat assassins are killer nominating."
While Sarah and Sam must killer nominate, Paul and Brandi have to uncover the killers and their success or not will determine the nominations.
Big Brother explained: "If Paul and Brandi guess the killers incorrectly, then these undercover celebrities will have got away with murder and will be granted immunity from this week's eviction, whilst those that they have killed will face the public vote.
"If however they are caught red handed, the killers themselves will face eviction."
Murderers Sarah and Sam delivered their first two of four secret killer nominations yesterday, putting Brandi and Paul up for the axe.
Overnight, they had to killer nominate two others by secretly placing horses heads in their bed.
The duo settle on Helen and Derek, reasoning it would make it harder for Paul and Brandi to work out who is behind the killer nominations.
If Paul and Brandi don't finger Sarah and Sam as the killers, then Brandi, Paul, Helen and Derek will face a double eviction on Friday.
But if they are caught, Sarah and Sam will be up for the axe - although they won't be facing the vote alone.
Stick with us for the latest!
Celebrity Big Brother 2017 continues tonight at 9PM on Channel 5.