I've seen this once before. Steve (Fourwings) will correct me if I'm wrong, I think it was a Four-spotted Chaser that and Emperor had in it's grips, munching away like it'd just opened a favourite sweet, decapitated it and contents being eaten with relish.
Once it had had it's fill, the body was dropped and it was away. Steve picked up the remains and handed to me. It was when the headless body curled in my hands that I yelped!
A great series of behavioural shots there Adam. Nature doing it's thing. Well done.