Eighty per cent of Leonardo's Last Supper has crumbled from the refectory wall. This documentary follows a trail of documents across Europe to a full-size canvas in a Belgian convent, and asks whether the master painted the scene twice.
When Leonardo's Last Supper was first shown in 1499 it sent shock waves through Italy and beyond. Twenty years of restoration have since revealed the awful truth: only about a fifth of the original paint is still on the wall.
Historian Jean-Pierre Isbouts follows a trail of clues and documents hidden for centuries, from the state archives of Florence — where a letter from King Louis XII asks the Signoria to lend him Leonardo — to Milan, Paris and Antwerp.
The trail ends at a remote convent in Tongerlo, Belgium, and a huge life-size canvas of the same scene. X-rays find under-drawing beneath every apostle except Christ and Saint John, which points at the master's own hand among his workshop's.
If the canvas is what the evidence suggests, it does more than add a painting to Leonardo's list: it shows what the ruined fresco in Milan once looked like.