The American obsession with evergreen tannenbaum is mostly based on a translated ditty by a teacher from Liepzig, who didn’t even write the tune. Done well, Christmas lights on naked winter trees appear to hang in the air: transparent structures, Faberge eggs and whorling seashells, traced in wireframe light. They speak of an ethereal world, or a suburb plunged into those parts of the ocean where fish carry their own lanterns. It’s the one chance the trees have all year to show off their lingerie.

Which is why they should really plant some already, thinks Cass, bright and shivering, arms high.