Chris Packham, Michaela Strachan, Gillian Burke and Iolo Williams broadcast live from the Dell of Abernathy in the Cairngorms. Tim Peake explains how autumn was born four and a half billion years ago.

It is Halloween so time to reveal the wild secrets of Troll Mountain on the Island of Rum. Chris reveals the surprising science inside an antler and the team go hunting for Britain's biggest spider.