S01E01Part 1

Carl Sillmans, a merchant banker firm midway through an expected merger with Dinslow Chemical Industries, is thrown into turmoil when its manager, Charles Makepeace, is found murdered. His flask had been poisoned, and as Detective Superintendent Lance Thorne investigates, he finds that there're a surprising number of people who may have wanted him dead. His wife Isobel, for example, whom he was planning to divorce for his mistress, Stella Tyson. His work colleague, John Field, who learned that day he was to be denied promotion, preferring an American arriving later that day, Dan Maitland, son of a rival firm. And then there's the mysterious threatening phone call he received the evening he died that suggests something far darker is happening than anyone realises.