When the wedding of internationally famous film star Lara Tyler (Alice Eve) to tweedy English author James Arber (David Tennant) is sabotaged by a paparazzo, they decide to relocate the event to the one place where the world’s press won’t find them: the sleepy Island of Hegg. But when ingenious paparazzo Marco (Federico Castelluccio) tracks them down in his mission to photograph the celebrity wedding of the year, Lara’s P.A Steve Korbitz (Michael Urie) and his assistant Emma (Sally Phillips) must find a decoy bride and think that local girl Katie (Kelly Macdonald) will be an ideal replacement. As Katie meets James, sparks fly, dresses get ruined and love gets complicated. Will Katie be able to fool the awaiting media and live up to being a stand-in for the world’s most famous movie star? Can an ordinary girl fill the most famous Manolos on the planet? And whatever will happen to her pledge never, under any circumstances, to fall in love again?