King of Hearts (1966) follows Private Charles Plumpick played by Alan Bates who has to disarm a bomb in a small French town that the German army made in WWI. Charles then wants to help local inmates at an insane asylum after he winds up there. He wants to save his friends and deactivate the bomb, but he might not have the chance. Alan certainly isn't insane for showing all his ass when he stands naked at the door of a convent naked with a birdcage. That's a great way to say hello!