Determined to sever his ties with the office, Gabriel Allon has retreated to the windswept cliffs of Cornwall with his beautiful wife, Chiara. But once again his seclusion is interrupted by a visitor from his tangled past: the endearing eccentric London art dealer Julian Isherwood. As usual, Isherwood has a problem. And only Gabriel can solve it. In Glastonbury, an art restorer is brutally murdered and a long-lost portrait by Rembrandt mysteriously stolen. Despite his reluctance, Gabriel is persuaded to use his unique skills to search for the painting and those responsible for the crime. But as he painstakingly follows a trail of clues leading from Amsterdam to Buenos Aires and, finally to a villa on the graceful shores of Lake Geneva, Gabriel discovers there are deadly secrets connected to the painting. And evil men behind them. Gabriel will once again be drawn into a world he thought he had left behind for ever, and will come face to face with a remarkable cast of characters: a glamorous London journalist who is determined to undo the worst mistake of her career, an elusive master art thief who is burdened by a conscience and a powerful Swiss billionaire who is known for his good deeds but may just be behind one of the greatest threats facing the world.