Next in the Enid Blyton for Grown-Ups series.
The Five go north to see their grandmother - Granny Barnard - who they haven't caught up with for many years, since she remarried. She is alone over the Easter weekend and so the Five decide to look after and reconnect.
They're shocked to find it's been so long that they don't recognise her at all. While they're there, they try to help her with her computer. They try first to fix her iTunes account, and then her internet banking - after all it's the least they can do! However everything they touch turns to dust. They end up getting her cut off from the internet, the gas and the electricity, and reduced to a World War II-style privations - that is until the toddler from next door comes in and fixes everything. They return home somewhat with their tails between their legs, only to discover that with their help Gran has learned to make videos, and has become an internet sensation.