Ten-year-old Josh Greenback lives in the idyllic village of Brookbrink, in northeast England. It is the first day of the school summer holidays and it begins to rain. Over the following days Brookbrink experiences flash flooding and the banks of the river Ahorn burst, flooding the whole village. Josh must leave his home and seek refuge in the community hall in the next town until the clean-up can begin. Josh's mum Emma sends him to stay with his eccentric granny in Scotland, while the house gets dried out and repaired from the flooding.

Pinecraft takes the reader on a wonderful trip to Ochtermuddy in Scotland. Whilst there, Josh meets a beaver called Timb. They quickly discover that although very different, they have many things in common, including the same hobby - building! Josh describes the Lego creations he has built over the years, and tells Timb about his favourite computer game, Minecraft. Timb can hardly believe the similarities, and describes his analogue version of Josh's computer game, which the beavers call Pinecraft. And so begins a wonderful friendship, based on similarities and differences, and sharing skills, as well as lots of fun adventures together. The story has a surprising and delightful superhero ending.