Where did the 'flashforward' concept come from?
"It came out of story conference, actually. Because the team's so big now, we've been having smaller meetings and having fewer writers in at once so we can throw ideas around easier. It's less formulaic than, 'Right, we need to do ten episodes'. We now sit and talk about what's really exciting and what we can do in smaller groups, and with a soap that we have the opportunity to play with and break the rules - and an audience that wants us to. This is probably as surprising as you can get! It just seemed like a brilliant opportunity to do something fresh."
Did you all jump at the idea?
"There are those moments when you have storyline meetings where somebody says something, there's an eerie shiver around the room, a moment's silence and then everyone starts smiling. It was certainly one of those and it just took off from there."
Did you know what the story was going to be before you settled on the concept?
"Yeah. After we'd settled on the story, someone said, 'We could film it, transmit it out of sync, then play the six months in the run-up to it and have six months fallout the other side of it'. Everyone went quiet and I looked a bit nervous when I realised that we'd have to shoot it almost straight away. We then had to work out exactly what happened in the run-up, everything that happened in the six-month fallout… it was just so exciting."
Did you have to change many of the planned storylines?
"We were already storylined through to April, so what this enabled us to do is to create some blank sheets. By coming up with the events in the 'flashforward', it meant we had to unravel some of what we'd already done. What it's actually done, though, it added loads more story to everything. It's put a real energy into everything."
Does it bear any resemblance to the hit US TV show FlashForward?
"No, there's a distinct difference between our 'flashforward' and the US show because the characters in the US show see what happens in the future, while we're giving our viewers their own 'flashforward'. Our characters are blind to the future. The ep was actually originally called 'Flashforward', but then someone said, 'Isn't that a new American series?!'"
In a nutshell, what happens during the 'flashforward'?
"It's Carmel and Calvin's wedding day and Calvin has learned, done and heard some dastardly things in the months running up to the day. It all builds to a head in the course of the episode - it's Calvin and Carmel's perfect day juxtaposed with the world closing in on Calvin - and he's eventually shot dead. Calvin's affected everybody somewhere across the board, be it positively or negatively. The episode features the consequence of his actions."
There are a number of shocks in the episode, aren't there?
"Yeah. One aspect that was very important for us was that it was a series of reveals. None of the characters in the episode are in the position they're in six months previously - i.e. what viewers are watching now. The idea is that the audience is trying to work out why the characters are behaving differently to what they know in the current timeline… it leads to so many questions!"
How many suspects are there at the end of the episode?
"There are 23 people in the episode and Calvin's unlikely to have committed suicide… so it could be anyone in the ep. Or it might even be someone who's not there… The most exciting thing about this story for us - in the build-up and the fallout - is that so many people have motives and means. When we sat and talked about the police investigation, it was hilarious! So many people are suspects!"
When will viewers find out 'Who Shot Calvin?'
There'll be a massive week-long story and the culmination of the week will be the reveal. That certainly isn't the end of the story, though. The reveal spirals into something else. We had to make sure that this wasn't a story that ended at the reveal."
Do you know 'Who Shot Calvin?'
"Of course I do! But there are only a handful of people that know... The murderer doesn't even know yet!"
You're asking viewers to invest six months to a year in the show – can you assure them that the payoff will be worth it at the end?
"The payoff will be absolutely worth it - the way that it plays out is not the way you expect at all. And the fact that it doesn't end at the reveal and it spirals into another story is very exciting. Viewers won't be disappointed."
Hollyoaks' 'flashforward' episode airs on Monday, December 21 at 6.30pm on Channel 4.
> Click here to read more from Lucy Allan about Hollyoaks' 'flashforward' episode in Soap Scoop!
> Click here to read our interview with Ricky Whittle