One Step Behind. Mittsommermord, englische Ausgabe

It is Midsummer's Eve. Three young friends meet in a wood to act out an elaborate masque. But, unkown to them, they are being watched. Each is killed by a single bullet. Soon afterwards, one of Inspector Wallander's colleagues is found murdered. Is this the same killer, and what could the connection be? In this investigation, Wallander is always, tantalisingly, one step behind.