Shaun Of The Dead - the self-styled romzomcom that Edgar Wright and Simon Pegg co-created in 2004 as a follow-up to their award-winning collaboration on the hugely successful Channel 4 sitcom, Spaced - was a hit at the box office (grossing £40 million worldwide) and won several prestigious industry awards, including Best Screenplay at the 2004 British Independent Film Awards, Best Horror at the Saturn Awards and Best British Film at the 2005 Empire Awards.

It also picked up two nominations at the 2005 Baftas: producer Nira Park for the Carl Foreman Award for Most Promising Newcomer, while the film itself picked up a nomination for the Alexander Korda Award for Best British Film.

All these plaudits, though, gave Pegg, Wright, and their extended creative team, an instant headache: how could they follow it up?

The answer, as it turned out, had more than a close link to Wright's past. Growing up in the small city of Wells in Somerset, Wright had been an inveterate watcher of cop movies, often staying up through the night to get his fix.

"I didn't have a video recorder until I was 17," laughs Wright. "I stayed up and watched TV. I did have a particular fixation with the cop films, particularly any of the Dirty Harry films, any of the gritty 60’s and 70’s films like Bullitt and The French Connection and all the 80’s films like Lethal Weapon and Die Hard."

Also a prolific amateur film-maker, Wright parlayed all his knowledge into a cop movie called Dead Right, made when he was just 18. When he and Pegg were discussing their first post-Shaun project, a number of ideas came up, but Wright still had a cop movie itch to scratch and so proposed that they do for the action movie what Shaun Of The Dead had done for the zombie movie: strain a particularly American genre through a peculiarly British collander, add several lumps of humour and serve.

"There's a great tradition of British crime films, but hardly any British cop movies, so that is what we're hoping to address," explains Wright. "And very few British cop movies actually use the iconography of the uniformed policeman. If you talk to people from other countries, they say, "they're so cute with their helmets and isn't it funny, they haven't got any guns."

So how do we a) make a big British genre film about British bobbies and b) how do we get lots of guns into it?" The answer they hit on was to go one bigger than Shaun Of The Dead and make a hugely ambitious action movie featuring Pegg in the lead role as crusading cop, Nicholas Angel.

Working Title, who had gambled successfully on Shaun of the Dead after Wright and Pegg had pitched it as 'Richard Curtis shot through the head by George Romero', were more than happy to reacquaint themselves with the Shaun team, and this time the pitching process was relatively straightforward.

"Simon and Edgar pitched the idea verbally and Working Title said yes straightaway, and they started writing" explains Nira Park, who produced Hot Fuzz with Working Title's Eric Fellner and Tim Bevan, and who also produced both Shaun of the Dead and Pegg and Wright's seminal sitcom, Spaced.

"It felt very different this time round knowing that at the end of the writing process the film would definitely be made. With Shaun, we never quite knew and the year after FilmFour (who developed SOTD) collapsed we really struggled to get it financed and it almost didn't get made, so I think knowing that Working Title were behind us from the beginning this time round made it easier."

The writing process began with a period of intensive 'research' during which Pegg and Wright waded their way through a list of cop movies, rewatching their favourites for inspiration. Of the 200 or so movies that were on the list - "it's great buying cop films from HMV and knowing that you can genuinely claim them back against tax!" laughs Wright - notable names included Freebie & The Bean, Lethal Weapon, Die Hard, 48 Hours, Busting, The Last Boy Scout, To Live And Die In L.A., Extreme Prejudice, The Super Cops, British classic The Blue Lamp, Point Break and Bad Boys 2.

The latter two, in fact, are directly referenced in the movie, forming an important part of Danny Butterman's DVD collection. "There's a bit where Nicholas and Danny are watching Bad Boys 2 and something that Martin Lawrence says has relevance to what's going on in our film," giggles Pegg. "So when we wrote the script we actually had a bit where Martin Lawrence says 'this shit just got real' like he’s commenting on our plot."

However, the film really took shape after an intense period during which Wright and Pegg shadowed police officers in London, Somerset, Gloucestershire and Wiltshire. "We interviewed lots of officers in London and we also toured about 15 rural stations.

We then spent a week interviewing different police officers and that was brilliant because they were so helpful and so candid, and lots of amazing details came out," says Wright.

Many of those details made it into the film, such as a brief mention of a hierarchy of sugary snacks which tardy officers are forced to buy, while Angel's police number came from a real-life PC who Wright and Pegg accompanied on an eventful ride-along. "We were driving down a country lane in Somerset when a voice came over the radio with an alert.

The PC stuck on the ‘Blues and Twos’ and we went hurtling down this country lane at 85 mph. Me and Edgar were like ohmigod!”
 
Fully stocked up on anecdotes and research, the duo set about writing the script, initially working out what Pegg calls the "willfully labyrinthine" plot on a series of index cards and a flipchart in the London office of their production company, Big Talk.

But the distractions of living in London soon proved impractical and they retreated to a rented flat in Wells to finish the draft.