Twenty years ago today, on 31 August 2006, Norwegian police recovered Edvard Munch's The Scream, taken from the Munch Museum two years earlier, in August 2004. Munch's Madonna went missing on the same morning and came back with it.

Stand close to the 1893 board and you see how little is there. Tempera and pastel on cardboard, much of it left unprimed, so the brown of the support breathes up through the colour and does half the work. The sky is laid in long dragged strokes, one pull of the brush after another, thin enough that the ridge of the board shows. There is bare card at the edges. That is a picture with no armour on it, and it spent two years away from the climate that had been keeping it alive.

So the harder part came after the raid: conservators sitting with the thing and deciding what could be mended and what would have to be lived with. Moisture had marked the lower left. They chose restraint over invention, and the painting went back on the wall carrying its history rather than a repair pretending nothing happened. In the photograph below, the two of them hang on dark blue: the figure on the bridge, and beside it the man in the black jacket with the cigarette. Both back in the room.