A PRIVATE ISLAND by JEFF RIAN Each summer for the past several years I’ve spent a few weeks on a private island on the border of Normandy and Brittany. There are two houses on the island, which belong to one family, one of whose members rents her house every summer to me and my girlfriend and our two young kids. I won’t name the island as a courtesy to the owners. The other house belongs to our friend’s nearly 80-year-old aunt who lives alone on the island, all year round. But in fact it is only an island twice a day, changing its identity with the tides. The island can be accessed by car when the tide is out, which allows up to six hours of coming and going, depending on the tide coefficient. One of those two times however, is usually when you are sleeping. The tide changes by…