Humphrey Bogart, in one of his greatest performances, plays the part of a talented screenwriter (Dixon Steele) who's disillusioned with the industry in which he works and is also critical of the quality of many of the projects that he's invited to undertake. His bitterness and hostility often manifest themselves in violent outbursts of anger and drunken rages. This behaviour and his general inclination to be uncooperative with other people in the business, lead to him becoming alienated and out of work for long periods. He does, however, at times also display a more human side, for example with his kindness to an old, out of work, alcoholic actor with whom he is friendly.
One evening Dix meets his loyal and long suffering agent, Mel Lippman (Art Smith), at a restaurant/bar to discuss a project to write a screenplay based on a new best selling novel. Dix feels typically sceptical about the merits of the book but nevertheless, agrees to read it. The hat check girl at the establishment has read the novel and is very enthusiastic about it, describing it as an "epic". Dix takes the opportunity to invite her back to his apartment, so that she can tell him the entire story thus relieving him of the tedium of having to read it himself. She agrees and after completing the task, Dix pays her and also gives her money to get a cab to return home.
The next morning, after her dead body has been found, Dix is interviewed by the police who suspect him of murder. Fortunately, one of his neighbours, Laurel Gray (Gloria Grahame) saw the young lady leaving Dix's place and is able to support his account of what happened. Dix and Laurel get to know each other and soon fall in love. This experience transforms Dix from being unmotivated and unwilling to take on work that he thinks is unworthy of his talent and he rapidly becomes very industrious and works extremely hard on his new screenplay.
Unfortunately, as their relationship develops, Laurel becomes increasingly aware of how bad tempered and jealous Dix can become and a combination of things that she's told by other people about his violent nature and also behaviour that she witnesses herself, make her start to fear him. Things get so bad that Laurel starts to use sleeping pills and when Dix proposes, she feels compelled to accept because she's so afraid of him. The means by which their relationship continues from that point leads to the movie's very unconventional denouement.
In the scene where he's interviewed by the police, Dix's reactions to the information he's given and the charges made against him are not conventional and the fact that he reacts with petulance rather than shock, horror or sympathy lead to him being seen by them as someone who's more sinister than would have been the case had he responded in the way that they would have expected. This passage of the film is interesting both because of its similarity to the predicament experienced by the main protagonist in Albert Camus' "The Stranger" (aka "The Outsider") which was published in the early 1940s and also because it provides another illustration of Dix's complexity.
Bogart is excellent in his particularly demanding role and Gloria Grahame gives a great performance in which she shows her changing feelings and increasing vulnerability in a very natural and believable manner.
"In A Lonely Place", rather like Dix himself, is less than straightforward as it initially appears to be a murder mystery but soon develops into a poignant, romantic melodrama. The complexities of its main characters and the feelings of hopelessness and futility that it conveys also make this movie very different from the mainstream dramas that audiences are more used to seeing.