Inspector Maigret is convinced that a man sentenced to death for murder may actually be innocent. To test this, he secretly organizes an escape from prison so he can observe the suspect’s behavior outside custody. As the man moves through Paris, Maigret follows him and slowly uncovers hidden motives, manipulation, and a deeper layer to the crime. The investigation leads Maigret to doubt the official verdict and reveals that the truth is more complex than it first appeared.