John Gregson is quickly christened "Septic" as he (sort of) arrives a Royal Air Force airfield at the height of the Battle of Britain. Everyone there is knackered - exhausted by the war, weary, tired and scared. They are led by the motivating "Tiger" (a decent effort from Jack Hawkins) who has long since mastered the carrot/stick approach to his flyers who are often little more than boys straight out of school or university. "Septic" is keen - but will he remain so? Can he remain so? People are dying all around him! It's actually quite a complex drama this. Some fine aerial photography and some familiar music help to illustrate just how perilous these men's daily lives were. The infrastructure that supported not just the pilots but their logistics and co-ordinating teams is also exposed in a way that cinema rarely tended to do - we realise a great deal more about just how the cogs and wheels interacted to makes the defence of the country against a determined - and outnumbering - foe was essential. A solid cast of British screen talent are in support - notably a rather stronger role for Michael Denison and, of course, you cannot have him without Dulcie Gray. The conclusion isn't what we'd expect, nor probably what we'd wanted either - but that adds a little authenticity to this well strung together wartime drama that is well worth a watch.