Ralph Richardson plays one of his military friends, though John and Harry already share a complicated relationship due to their attempts to court the same woman Ethne (Jane Duprez). Richardson's role is pivotal in the film, as several scenes focus squarely on him, though his character's purpose and actions are always in relation to Harry's journey, so I do feel he is supporting. Richardson, despite having a less notable film career, though not unremarkable, than his contemporaries of the British stage, John Gielgud and Laurence Olivier, actually started out with a greater comfort in regards to cinema than either of them. Richardson, as he also proved in The Citadel and even the Ghoul of all films, has a natural grace on screen which works quite well with the part. Richardson finds the right approach in the early scenes with Durrance by bringing an underlying understanding in Durrance's interactions with Harry, despite alluding to some understandable consternation due to his rejection by Ethne. Richardson finds the complexity of Durrance's attitude towards Harry well, never overplaying either side of the man's personal feelings. Richardson handles this within bringing the right strict manner fitting for a man who certainly believes in being a soldier.
After Harry resigns the film follows Durrance's time in the Middle East where he does not exactly get off all that well as a soldier. Richardson is terrific in portraying the physical degradation of Durrance as he slowly succumbs to heatstroke. He's equally good in portraying the mental breakdown in Durrance. Richardson takes a decidedly nontheatrical approach in realizing almost in a certain surprise in Durrance's view during this time as almost he can't believe how ill equipped he's found himself not only in terms of current predicament but as a soldier. Richardson importantly never shows this to be as though Durrance is some sort of goof, but rather finds the suffering Durrance goes through in a genuinely harsh fashion. This only worsens as a battle occurs while he is in this state which leaves only Durrance, and a disguised Harry living. Harry goes about attempting to save Durrance whose state which only worsens during this time. Again Richardson is very good in his depiction of the delirium that that inflicts upon Durrance due to his heat stroke. Richardson finds this confused state by showing bluntly just how much of a mess Durrance is bringing the right constant unease in terms of state along with a harried method of speaking.
Eventually Harry gets Durrance to safety without Durrance ever knowing it was his old "cowardly" friend, unfortunately Durrance has been left apparently permanently blind by the experience. Richardson is very moving in finding the new state of Durrance back at home, where he does find sympathy from Ethne who agrees to merry him. The blindness itself Richardson effectively portrays particularly since he does not attempt to draw too much attention to it. The most remarkable aspect of Richardson's work is his portrayal of the change in Durrance as a man bringing out the right earnest modesty in man who has had the soldier in him painfully ripped out. Now really the emotional climax of the film does not belong to our leading character Harry, as his success at proving his bravery is acknowledged largely off screen, that even includes his own reunion with Ethne. That climax is really all left to Richardson which is all the better I suppose due to John Clements's choice to give a rather cold performance as Harry. Richardson makes the most of this chance in the scene where Durrance comes to realize what Harry had done for him, and decides to give up Ethne. Richardson is heartbreaking as he internalizes the decision brilliantly throughout a single scene, and his brief reaction upon realizing Harry's deed is outstanding as Richardson effortlessly conveys the severity of this revelation in Durrance. This is a very strong performance by Ricahrdson as he anchors the film throughout rising above the call of duty, since he still really is not the lead.