Parents facing the next couple of months of summer vacation cooped up with restless kids may relate to the challenges that divorced British dad David (Matthew Goode) and single American mom Alice (Paula Patton) face after deciding to combine their family holidays. With only a few months of dating behind them, they’re determined to reveal their newly minted coupledom to David’s thirteen-year-old daughter Ros (Teddie Malleson-Allen) and her younger brother Robbie (Billy Jenkins), as well as Alice’s kids Samantha (Ashley Aufderheide) and Maudie (Ellie-Mae Siame).
Arriving separately with kids in tow at their too-cute rental cottage on the spectacularly scenic coast of Cornwall, the couple immediately encounters resistance to their dating disclosure. Ros, a bit of a dreamer still clinging to the faint hope that her parents may reconcile, pushes back against any maternal gestures offered by Alice, who’s already struggling to manage her rebellious thirteen-year-old Samantha, defiantly nicknamed Smash. The younger kids seem to take it all in stride though, with Robbie devoting himself to video games on his tablet and Maudie eagerly exploring the area, where the group soon encounters Tristan Trent (Russell Brand), the haughty property owner and master of the manor on the hill.
More surprisingly however, the kids discover a secret beach and a mysterious creature living beneath the sand who not only speaks to them, but grants wishes as well. Looking like a mashup of E.T. and Oscar the Grouch dusted with a coat of golden fur over his greenish skin, Psammead (Michael Caine) claims to have spent hundreds of years on that very strand. Cleverly cornering Psammead, who grouses that “wishes are bad news” with Caine’s distinctive Cockney twang, the children learn that he only grants one request a day and that his paranormal powers wear off at sunset.
Pop stardom, magical flight and time travel figure among the kids’ wishes, although they remain unaware that Trent continues to watch them closely, eager to divert Psammead’s talents for his own amusement. Brand’s arrogantly idiosyncratic interpretation of the eccentric landowner emerges as the only really amusing performance throughout the movie, setting a low bar for most of the remaining cast.