Back when Robards was the head of the departmeant, Cass would whine at the turn his job has taken. For a brief moment when Percy took over, he'd stayed more at home than ever. He'd had assignments that fitted his skills and intelligence, less things like this, which could be done by anyone who knew how to hold a wand.
Yet he didn't whine about being sent away anymore. He understood why he was being kept from the office, why he'd been sent to clean up the mess of the werewolves yesterday, why he was now here disguised as a Muggle police officer watching a bunch of people move about Stonehenge in wait of the sunrise.
Then he'd been sent away because Robards didn't have the intelligence to see his skill. Now he was being sent away because Percy couldn't bear to see him. He wouldn't blame him, wouldn't whine. He understood.
That didn't make it any more entertaining or fun, and as dawn closed in on them, he was leaning against the van half asleep. Until he heard the first scream.
The sound was so unnatural for this assignment that he jumped, at first not understanding what he saw. A man, floating in the air, hanged on his hair – another swelling like a balloon... In that moment the man exploded, covering everyone with parts of him. It was disgusting, and the Muggle police next to him threw up while rambling about this being impossible.
Unfortunately, he knew better.
Drawing his wand he cast a patronus to the Aurors office, but also, after a slight hesitation, to Harry. As much as he liked Harry, he wasn't overly fond of the Order, but as the screams became insistent, and people started to run, there was no denying that they needed them here. The Muggle police officer next to him was in shock, and he cast the first spell at him, then his co-workers, clouding their eyes until they saw guns and villains instead of wands and magic.
That's when he caught a glimpse of Rodolphus, and somehow his mind went blank as he was filled with a rage he'd never felt before. Blinded to everything but the sight of the man who had caused him the joy in his life, who had his mother somewhere in a dungeon, who possibly tortured her… He didn't think, didn't hesitate, he ran for him – as Aurors and order members started to Apparate in – he could think of nothing but Rodolphus, go for nothing but Rodolphus, casting a blasting hex in his direction even before he reached him.