This is the opening charge of the battle against Galba, after our intrepid hero and his ally Quen Boadicea have conquered Britannia, and crossed the sleeve (i.e. the channel) to invade Gallia.
I found it interesting because I don't think I've ever seen an LA screen with so many missiles caught in flight before
And, as you can see, those Velites are about to find out for themselves just how dulce et decorum it is to pro patria mori.