From their new home on the magical island of Brownsea in Dorset, Bill Oddie and Kate Humble return to follow the most dramatic season of the year, aided by a cast of red squirrels, sika deer and spectacular birdlife on the lagoon. Meanwhile, Simon King's quest to unravel some autumn mysteries begins with the fallow deer rut and Gordon Buchanan braves cruel storms as he follows the fate of the grey seal colony on the Farne Islands, as young are born in harsh conditions.