It's Mary's birthday and the islanders celebrate it by having a beach party. Robbie plans to leave Ronansay. It's not really of his choosing but he thinks he's wasting his time with the kids and Abby. But to his surprise, Abby's response is dismissive - why does he want to leave? So with a new purpose, Robbie faces his challenge. Kenny takes charge of the 'how to talk to your kids' lessons and Robbie's unexpected success results in his making some real progress with Alfie. Carolyn, feeling depressed and isolated, misreads Dr Talbot's professional concern and kisses him - leaving him speechless. Big Jerry goes to see Carolyn and realises that she needs Alistair. He goes to find him - Big Jerry offers to take his place on the boat, and Alistair, after a few home truths given to him by Big Jerry, decides to return Ronansay. A stranger turns up at the school asking questions. Having lied on an Education Authority register Douglas fears he's been found out. Gordon persuades Abby to conspire with him into being economical with the truth, but it proves fruitless - the stranger returns, and this time it's with the police. He represents Ida's ex-husband who wants custody of Peter. Malcolm along with the Islanders band together to protect them but Ida and Peter have no choice - a distraught Malcolm is forced to accept that they have to secretly leave the Island if they are not to be deported.