“The Long Call” launches a new police procedural series starring DCI Matthew Venn, a fussily dressed, withdrawn, intelligent policeman driven by his own history to pursue justice. Ann Cleeves specialises in locales and here she brings to life North Devon, a suprisingly obscure corner of England with its rivers and coastline and touristy towns. A drunken vagrant has been stabbed on the beach and what might seem a simple tale thickens and darkens as Venn, helped by DS Jen Rafferty, one of those second-rank characters Cleeves portrays so well. The case intertwines with Venn’s own life, involving as it does a community center managed by his husband. Cleeves provides a complexly stewed plot and a steady pace that accelerates towards a twisty end. Not as immersive, perhaps, as the Vera and Shetland series, the advent of Venn in this new series called Two Rivers, is most welcome. A classic diversion.