Dalgliesh (1983)

Commander Adam Dalgliesh is asked by a friend, Home Office Minister Sir Paul Berowne, to be aware correspondence of a personal nature he's received. He's not being blackmailed and so there's nothing to investigate per se and he only wants Adam to keep an eye on what's going on. Sir Paul's personal life is somewhat complicated. He lives in the shadow of his late brother Hugo and has little time for his wife Barbara who is having an affair with Stephen Lampart. She is now pregnant but insists that the child is his. He's fed up with it all and decides to chuck it all in....