A plaque outside 7 rue des Grands-Augustins in Paris records that Picasso lived and worked there, and that the building is the setting of Balzac’s The Unknown Masterpiece. Picasso moved in after reading it. In the story, the painter Frenhofer is convinced he has made a masterpiece; when others finally see it, it is unreadable. The plaque states all this in the flat voice of public record. Behind it is something less settled: one of the most successful artists of his century choosing to live inside the story of a painter no one understood.

Double is two mirrored boxes. Most of the time they look sealed and simply reflect the room. Now and then a light inside comes on, and the plaque’s text, engraved on a mirror within, appears on the same surface as your own reflection, then goes. To read the inscription, you have to see yourself in it. The two boxes flicker slightly out of step, so the pair is never quite identical.