Not as good as I thought it would be, because I had expected a serial killer story. "The Secrets in Their Eyes" is about a retired Argentinian federal justice agent Benjamín Espósito, who is writing a book about an old case, where a beautiful young woman was raped and brutally murdered. It seems the case possessed him then that he and his assistant Sandoval followed a lead, against their boss's advice. Meanwhile, Espósito fell in love with his new department chief Irene Hastings, but stood back as she was out of his reach.
They could catch the killer eventually, thanks to Espósito's sharp eyes; but the killer was free because he had been working for the government as an informant. The release of the killer made Espósito's life in danger, especially after Sandoval had been killed. Espósito decided to leave: leave the city, his work, and Irene.
20 years later, he is back, and finds that the thing that haunts his life for the last 20 years, was actually taken care of then. It's very sad, really.
The scenes move back and forth, with the same cast, but with the superb make-up, we won't have any difficulty to tell if the scene is telling the recent time or the past.