Gustaf Torstensson quietly chants “Mea culpa, mea culpa,” as he drives to his death. His son Sten Torstensson, a friend of Inspector Kurt Wallander (Kenneth Branagh), begs the detective to investigate the suspicious case — Wallander is his last hope. But hope has all but drained from Wallander’s life, as he’s now on indefinite leave from his work and has been all but forgotten after enduring an on-the-job trauma. When Sten is found dead, an apparent suicide, Wallander is drawn back to inquire. The clues and suspects are provocative enough — postcards with death threats, a respected and reviled philanthropist working in Africa and a former cop tormented by his own personal demons. But Wallander’s reentry is an uneasy one, and even as the case comes together, his fragile stability and increasingly questionable judgment are severely tested. Rupert Graves guest stars in The Man Who Smiled, based on the novel by international bestseller Henning Mankell. (One episode; 90 minutes, TV-PG)