Claude Lacombe, presenter of the famous television program "Aux frontières du Cosmos" is found murdered in the middle of a cornfield. His body rests in the center of a crop circle. The unfortunate would have fallen from a great height. Faced with the mysterious circumstances of this death, the newspapers do not hesitate to speak of a "murder of the 3rd type" committed by extraterrestrials. Struggling with a surreal investigation, Annie Gréco must keep a cool head, especially since Beretta is captivated by the astrophysicist sent by the ministry and begins to believe in flying saucers. The truth, of course, is elsewhere, but we still have to succeed in demonstrating it...