Show regulars Claire Cooper (Jacqui McQueen), Andy Moss (Rhys Ashworth) and Anthony Quinlan (Gilly Roach) will be among the stars taking centre stage in the bonus edition of the teen soap, which is to feature a dark storyline focusing on Darren Day's dangerous character Danny Houston.
The drama kicks off when returnee Kathleen McQueen (Alison Burrows) threatens to report daughter Theresa (Jorgie Porter) to the police after discovering the truth about Calvin Valentine's murder. In return for her silence, she demands £2,000 - leaving her screen family facing a big predicament.
Later, Danny catches Jacqui and Rhys cheating during a game of poker in a bid to raise some funds. Furious that the pair have tried to double cross him, Danny immediately orders them to hand over the money they stole and more.
However, with his feelings for Jacqui still running strong, Danny also makes a second sinister suggestion - vowing to wipe the debt clean if he can have one night with the feisty barmaid.
Desperate to save Jacqui from having to sleep with the gangster, Rhys and Gilly team up with the McQueens to find a way to raise the cash. They also seek help from menacing Brendan Brady (Emmett Scanlan), who is brought in to con his old friend as the plot thickens.
As the action reaches a climax, Rhys and Gilly kidnap Danny's drug runner Sophia - but end up in a desperate situation when she turns a gun on them. Meanwhile, Jacqui finds herself surrounded by Danny's heavies and is forced to strip at knife point - will she be saved in time?
The one-off episode sees special guest star Donna Air take on the role of Sophia. Speaking of her casting, she commented: "I am thrilled to join the cast of Hollyoaks for the late night special. The cast and crew have been so welcoming, and I'm excited to be part of such a hit show. The storyline is great fun and I love playing the role of Sophia, she's brilliant."
Hollyoaks' late-night special - titled 'King of Hearts' - airs on Thursday, December 16 on Channel 4 and has been tipped to spark a big new storyline that will affect the lives of the characters involved forever.