There is bright sunshine on the dock of Cardiff Bay, but inside Studio 6, the lighting crew has set the weather to overcast. I’m standing in a fake courtyard outside a fake terrace of period cottages beside a fake 40ft pine forest. It all looks so real, it is momentarily surprising to step through a fire exit into a car park.

Wolf Studios occupies 250,000 sq ft of former factory buildings and very little of it is not being used to film the first television adaptation of Philip Pullman’s His Dark Materials. As the first of three series debuts on BBC1 next month, the stakes couldn’t be higher. After all, the trilogy is a cultural phenomenon in its own right — critically acclaimed, controversial, reviled