What if something happened long ago that still makes you sad? Graham is Molly and Beth's favourite uncle, so they really want to help him fix the past - and since the girls know of a mysterious door that can take them back in time, maybe they can! But how can they find who they're looking for without apps or social media? And what will the girls make of the 60s, where the hairstyles are wild, the slang is weird and no one's heard of ciabatta?

And can they help Graham fix a friendship that was destroyed back in 1960? The girls soon discover that fun with friends is just the same whatever time you live in and that real friendship lasts forever - even when you're apart.