I’ve never been to the V&A’s Museum of Childhood, let alone after hours. But in the expansive hall and gift shop, one corner has been set up as a playing space for Popup Opera’s Hansel & Gretel. There are shelves of toys and other souvenirs behind us, and sterile glass display cases behind the stage. Our cozy pocket in the grand room has a sinister gloom surrounding what with the autumn evening’s quickly fading light. It’s a suitable space for a story that mostly takes place in the woods overnight, when fairies and witches come out to play.