PBS's Masterpiece will air three episodes based on Henning Mankell's Kurt Wallander mystery series beginning this coming Sunday, May 10. Kenneth Branagh stars as the Swedish sleuth who fights crime in the seaside town of Ystad. The first episode is based on Sidetracked (Vintage, $14.95, 9781400031566/1400031567). The second, based on Firewall (Vintage, $14.95, 9781400031535/1400031532), airs Sunday, May 17. And the third, based on One Step Behind (Vintage, $13.95, 9781400031511/1400031516), airs Sunday, May 31. All three episodes begin at 9 p.m. EST. Online resources for book groups will be posted this week on pbs.org/masterpiece/bookclub.