See! This is how you do romantic comedy! You don’t “make it funny” by populating it with adults who act like childish brats and behave in ways not recognizably human but allegedly kooky. You make it funny by putting real people in a situation that’s a just tad fantastical and watch them cope with it. Such as in the middle of a project to put Scottish salmon in a previously nonexistent waterway in the highlands of the Arabian Peninsula. Dr. Alfred Jones of the Department of Fisheries and Agriculture (Ewan McGregor: Haywire) says of the project, with deadpan minimalist scientific bewilderment: “It’s theoretically possible in the same way that a manned mission to Mars is theoretically possible.” But Sheikh Muhammed (Amr Waked: Contagion) has £50 million, a dam-spawned artificial river, and a dream (of fly-fishing), and Britain needs some good news from the Middle East. And so Fred is ordered, by the Prime Minister’s press secretary (Kristin Scott Thomas [Bel Ami], apparently imported, hilariously, from In the Loop), to make it happen. Which he will at least try to do with the help of investment consultant Harriet Chetwode-Talbot (Emily Blunt: The Adjustment Bureau). Oh, and here’s another tip for rom-com filmmakers: try not to make it feel inevitable that our lovelorn protagonists end up together. There are, wonderfully, no foregone conclusions to be found in this charming and cheeky film: Fred and Harriet are romantically entangled elsewhere, and of course the salmon project is entirely preposterous. But it’s the journey — of “faith and fish and science” — that’s crucial here, fueled by a philosophy that embraces the adventure of not living life “in theory” but turning something crazy and impossible and magnificent into reality. Or at least trying. Based on the novel by Paul Torday [Amazon U.S.] [Amazon Canada] [Amazon U.K.] and beautifully adapted by screenwriter Simon Beaufoy (Slumdog Millionaire) and director Lasse Hallström (Dear John), this is a hugely rewarding tale of dreaming big, building big, and living big.