Surprised by this

Only gave it a look because it starred Sylvia Syms but it's a really good film. Patrick McGoohan plays a young prison warden who is chosen by an older warden to help in the execution of Syms husband.
If that sounds grim, it is. But perhaps because it's based on a Brendan Behan play it tells the story with subtlety, without melodrama and no one is a monster. Also Syms, McGoohan and Walter Macken are very good.