Lewis S04E03 - Your Sudden Death Question

Six couples arrive at out of term Chaucer College for a quiz weekend with a five grand prize. One of the contestants,womanizing know-all Ethan Croft,is murdered and another,Robyn Strong, is an old flame of his, disappointed he failed to recognize her. Ethan was a brilliant linguist but he was sacked from the college years earlier after an affair with a student, now married to another quizzer,whilst Eve,Robyn's quiz partner, is the next victim,after she has been heard arguing with Ethan. Passion, however, is not the motive, the killer being one whose guilty secret was exposed by Ethan's language skills over a past business transaction - with at least two suspects in the frame.