Antonio Larussa has apparently committed suicide in his own house with a complicated system of wires that transform his wheelchair into an electric chair. Everyone is certain that this is an open-and-shut case except for Montalbano (Luca Zingaretti). As he conducts his investigations, he uncovers a complicated plot involving Antonio's brother Giacomo (Luigi Maria Burruano), a high school physics teacher subsequently accused of murdering Antonio; and a childhood sweetheart of both brothers (Ileana Rigano) who has returned to the local area after the death of her husband. Meanwhile Mimi Augello (Cesare Bocci) investigates a separate murder of a loan-shark, which turns out to have a vital bearing on the Larussa case. Alberto Sironi's production goes through various twists and turns with a surprise ending that takes viewers by surprise. The only snag with this particular mystery is that it leaves certain loose ends of plot: Antonio has quite literally fried to death in his wheelchair, yet it seems that Giacomo did not notice anything amiss when he came back to Antonio's house. Surely the stench of burning flesh would have disturbed anyone? Nonetheless this story shows the human side of Montalbano, especially at the end when he allows the chief suspect a few moments of freedom on his own before taking him into custody.