In a university lecture theatre, only two students remain to sit their oral exam in Criminal Law under the watchful eye of the demanding Professor Peña. Mario, a long-standing but clumsy student, barely manages to get through it. Clara, his friend and brilliant fellow student, dazzles with her answers. But after she has finished, the professor poses an unexpected question: what mark does Mario deserve? The mark the student decides on will be his final mark. What seemed like a gesture of friendship turns into an ethical dilemma when Clara realises that her decision could cost him his professional future.