Fly versus Spider

Interesting interaction in the nettles at lunchtime. There I was watching a Nursery Spider (they're big old beasties in a UK scale of things) when I noticed a Scorpion Fly behind, with what looked like a silk-woven snack (though I don't know if Nursery Spiders do that being 'pouncers'?). Anyway....
The Scorpion Fly narrowly avoids a pounce, but is clearly still intrigued by the package, which the Nursery Spider is now guarding, as the two have a stare off.... (stacked image for focus as the Fly was an inch or two lower).