Likeable performances are the salvation of this middling coming-of-age story, which gets itself in a tangle by mixing elements familiar from both ‘Wish You Were Here’ and ‘An Education’. Jessica Brown-Findlay is this year’s Emily Lloyd or Carey Mulligan as the impossibly sassy 17 year old who turns heads at a twee seaside B&B where author Sebastian Koch trades on his one-hit novel. Spouse Julia Ormond is impatient for a successful follow-up and daughter Felicity Jones keeps her head down in the crossfire. Jones excels in the less showy role of the gifted student who’s headed for choppy emotional waters just as she’s bidding for Oxbridge, yet Tamzin Rafn’s script never decides who’s the centre of attention – her or the sharp-yet-flaky Brown-Findlay making unwise mileage out of a purported family connection to Conan Doyle. The two young actresses keep us engaged, though the movie as a whole suffers from a certain predictability, while the clunky scene explaining the metaphorical import of the title is a real groaner.