However, the missing gun - which has been stolen from the safe at The Loft - is playing heavily on his mind. In addition, his sister Sasha still refuses to attend the ceremony. Will he manage to persuade her to forgive him for leaving Warren to die?
Hoping to discover who stole the gun, Calvin watches CCTV tapes from The Loft. However, he's unprepared for the shocking truth...
Confronting the original thief, Calvin's gobsmacked to discover that someone's stolen it again. With the wedding just hours away, and a death threat hanging over Calvin, who has got the gun?
Cheryl detects friction between Malachy and Kris and is stunned to discover why - Mercedes has been sleeping with Calvin.
Meanwhile, over at the McQueens', Jacqui tires of Mercedes's sourness over Carmel's wedding. Mercedes scoffs at Carmel's sickly-sweet dreams and snaps at Jacqui that Calvin isn't a match made in heaven, before revealing that she's been bedding him behind her sister's back.
Enraged, Jacqui goes after Calvin but he calls her bluff - what's she going to do about it? Will she ruin her sister's special day with the terrible truth? Jacqui warns Calvin that he's going to get what's coming to him. Is Jacqui capable of murder?
Elsewhere, Dave and Charlotte take India to a country house for a birthday surprise - and it turns out to be a murder mystery event. There's tension as Josh makes an unwelcome appearance.
The evening takes a turn for the worse when Olly and Ste come to blows over Amy. But who will be the first murder victim?