The story is about Adam Pollo. In the introduction, we are told that he wasn't too clear if he was getting out of the army or a psychiatric institution, though, in the book, he says that he is a deserter and mentions the army on more than occasion, even associating with US army types. OK, unreliable narrator. We get it. What we do know is he arrives at a resort on his motorbike, which he proceeds to dump in the sea, to give the impression that he has died. He moves into a villa which has either been abandoned or where the owners have not visited for some time. He doesn't do too much there and what he does is given not as a plot but in a series of vignettes, with the chapters given letters rather than numbers.
He starts by writing to a young woman, Michèle, though it is not clear if he sends these letters. She later arrives at the villa by bus, for a short while and we know he has written to her, as he has sent her a crude and not too helpful map of how to find the villa. We learn that had raped her in the past but she does not seem to have reported the matter to the police and does not seem too bitter about it. His other adventures involve walking on the beach and talking to the people there; hanging out with a dog, whom he accompanies into town, till the dog abandons him, attacking a rat he finds in the villa with billiard balls, till he kills it; hanging out with American soldiers in a bar; visiting the local zoo, where he annoys a panther; going to shops where he asks for records by fictitious artists (though, one he does ask for - Mac Kinsley Morganfield - is almost Muddy Waters' real name (McKinley Morganfield)) and then decides he will read one page of a book every day and he starts with Richard Hughes' A High Wind in Jamaica; he sees the body of a drowned man, fished out of the sea by the emergency services (a newspaper clipping shows that it was a likely suicide). He goes looking for Michèle, trying to track her down through her parents and through a friend. Eventually he finds her, with an American tourist. He gets unpleasant and they call the police. He manages to escape but the police, presumably on information from Michèle, turn up at the villa and again he only just manages to escape. In the meantime he has started writing his procès-verbal. In French, this word (the title of the book in French) means written report. It is not clear why the English version has been called The Interrogation, which can only refer to the interrogation Adam will receive at the end of the book in the mental institution. Adam's procès-verbal consists of his writing down his thoughts and actions at this time, often somewhat garbled, though often matter-of-fact accounts of his activities. Le Clézio gives us a bit of postmodernistic playing with the text, by having bits crossed out and bits missing, even middles of words.
Once he escapes the police at the villa, Adam goes to the town square and starts haranguing the crowd, calling on them to give up everything, so that only we human remain. We learn the results of this harangue from a newspaper article, which tells us that he has been arrested and taken to a mental institution. Interestingly enough, there is a much longer accompanying newspaper article about the discovery of the bodies of two German tourists off the coast of Corsica. If this is relevant, we are not informed why. The book finishes with Adam in the institution, where he is interviewed by a group of student psychiatrists. He both gives a good account of himself and shows himself knowledgeable about current psychiatric issues.
That Adam is the standard alienated man of twentieth century literature is clear, found in Kafka, Camus and many others. He feels little reaction to issues such as his rape of Michèle or the drowned man. While he has some feelings for Michèle, it is not clear if they are any more than sexual. At times, he is not much more than an annoying little punk. At others he shows himself to be intelligent and educated, for example quoting Francis Thomson's The Kingdom of God, in the original English. In the mental institution, one of the students maintains that he is not insane, though she is chided for her premature opinion by the doctor; nevertheless he is able to hold his own against them. That he had issues with his father is clear from a letter he receives from his mother but that does not explain it all. Of course, as Le Clézio has made clear in the introduction, there is no explanation, as this book is not realist. And, at the end, he also leaves it open. While the story is finished, he says, Wait. You'll see.