It was The Light Between Ocean’s turn to take its festival bow at the Lido’s stately Palazzo del Cinema, and the bright lights of the carpet contrasted sharply with the somber mood of M.L Stedman’s story adapted by Derek Cianfrance into his third feature (after Blue Valentine and The Place Beyond the Pines). The narrative transports us to the remote Australian island of Janus, where brooding WWI veteran Tom Sherbourne has taken a post as lighthouse keeper with his bright young wife Isabel (Alicia Vikander). The young couple’s life is marred by miscarriage and when a boat washes ashore with a baby and her dead father onboard, they succumb to the natural instinct to adopt the infant – instead of reporting the shipwreck and surviving child. A fateful decision, which will have inexorable consequences. We spoke to Vikander (at her second festival here after last year’s bow with Danish Girl) about Venice, the story and the challenges of playing a mother.