Corin Hardy kept cool asking Nick Frost to join horror film Whistle

Whistle director Corin Hardy didn't want to "get too excited" when he offered a part to Nick Frost in case the actor turned it down.

The Nun director's new horror follows a bunch of unwitting high school students who discover a cursed object, an ancient Aztec death whistle, and learn the hard way that blowing it summons their future deaths to hunt them down.

As a longtime fan of Frost's, Hardy had hoped to work with the Shaun of the Dead star for a while, but he didn't want to get his hopes up when he offered him the role of teacher Mr. Craven.

"I've known Nick for a long time through (director) Edgar Wright, ever since the Spaced days," Hardy told Cover Media, referring to Wright and Frost's 1999 TV show. "I've always been a fan, always wondered, you know, like, 'Oh, I wonder if I can get Nick in something?'"

"And then (with Whistle), it's sort of like, you don't want to get too excited (in case) you don't get someone, but Nick read it and said yes, so that was a really nice opportunity to have him fly over."

Hardy revealed that the Hot Fuzz star arrived in Canada the night before his first day on set and was shooting his scenes the following morning.

Of Frost's week on set, the British filmmaker added, "It was great to have him and he brings a certain levity to it which the character needed as well... He's got some very subtle (comedic moments)."

Elsewhere in the interview, the Gangs of London director explained that most of his cast - which also includes Dafne Keen and Sophie Nélisse - would play themselves as well as their future deaths "in some form", although the sequences where they come face to face also required doubles in full-body prosthetics.

"It's fine when you read the script and it's like, 'Their death is doing something to them,' but that means you do have to have someone who looks just like them in some way or whatever," he shared. "So Nick Frost had a double, we had to cast someone that had a sort of (similar) bone make-up appearance that we could then do full prosthetics on to be Nick Frost's future death."

Whistle is released in cinemas in the U.K. and Ireland from Friday 13 February.