Every day, from his window, Samuel watches as a woman drops off her two children at the bus stop. He is so fascinated by her that, one afternoon when he cannot be at his window to observe her, he leaves his camera programmed to take pictures of her picking up the children. Later, when he looks through the pictures, he not only sees his platonic love, but also an unexpected event that has been photographed. That day, on that corner, a group of teenagers provokes one of the neighbour's dogs, which manages to jump over the fence to attack and ends up killing one of them. Samuel decides to hide the pictures and, overcoming his shyness, ends up approaching the woman. Her name is Marina, she is recently separated, and the daughter of a high-ranking officer, Captain Olmedo, who is in charge of dismantling the city's military headquarters. Olmedo, a strict man who likes to do his job right, ends up dead in his house, with a bullet from his own gun, through his chest. His daughter Marina does not believe the official version of the suicide and she hires Cupido, a peaceful detective who will discover hidden secrets as well as the tense relationships of those that surround them. He will investigate Olmedo's military colleagues, his daughter's ex-husband, and even the anaesthetist who cared for his wife during her plastic surgery. There are reasons that make all of them suspects.