Near the end of his life, the great Romantic artist Eug-ne Delacroix (1798-1863) painted one of the most enigmatic episodes from the Bible: Jacob wrestling with the angel. This painting, which decorates the wall of the Chapel of the Holy Angels in the Paris church of Saint-Sulpice, is Delacroix's "spiritual testament". But Sain-Sulpice is a mysterious church where everything happens behind the scenes. A fan of Inspector Maigret, Jean-Paul Kauffmann investigates the painting and the church, paying particular attention to its hidden history. He searches for clues in a bar in Dieppe, a castle in Quercy, a village in the Argonne, an oak tree in the forest at S-nart, even a golf course in the Loiret. The trail leads him to an art critic, a lecturer at the Louvre, and a sculptor who has a studio in the attic of Saint-Sulpice itself. All these intertwining threads finally come together in a central motif in which Kauffmann himself is involved. There comes a time in which everyone must wrestle with the angel.