Bellatrix had barely had time to cast the Mark before that bloody Potter woman was almost in front of her - she was fast, but dammit, Potter was faster.
No matter - this was just a warning of things to come, as far as she was concerned, although almost nothing would make her happier than a well-aimed Avada Kedavra and the eruption of little Lily Potter into a pretty green flame.
Flame, fire - she loved it. Rod had joked that she was little better than a Muggle pyromaniac, and she had to admit it was true ... other than the "Muggle" part. THAT had earned him a smack somewhere painful. But she couldn't deny that she loved a good fire, and the home of the Chosen One burning to nothing made her smile.
And it was not a nice smile.
And it would scare the hell out of anyone who witnessed it, but the chaos made observation difficult.