The protagonist of the play is William Maitland, a 39-year-old English solicitor who has come to hate his entire life. Much of the play consists of lengthy monologues in which Maitland tells the audience about his life, a life he now regards as an utter failure. He readily acknowledges that he is bored with his wife and children, and just as bored by the petty, meaningless love affairs he's been carrying on with other women. His career revolves around sordid divorce cases, and he's come to despise both his clients and his colleagues. Maitland drinks heavily, and enjoys bullying and insulting everyone he comes into contact with.
In Act One, like a prosecutor presenting a case, Maitland brutally shows the audience the utter despair and mediocrity of his life. In Act Two, Maitland's crimes receive their due punishment, as he is deserted by everyone he ever cared about, including his clerk, his mistress and his wife. At times the play uses the technique of intercut monologues, which are arranged like dialogue but involve no communication between the characters.
The role of Maitland was created by Nicol Williamson who played the role in the original West End production of Inadmissible Evidence, in its Broadway debut, and in the 1968 movie version. In 1965 the play was performed at the Wyndham's Theatre, Charing Cross Road, London; Williamson played Maitland, whilst John Hurt played the part of Jones.