Alecto's posture immediately changed. She shifted away from her brother so she could give him a look. Her lips pursed even tighter as she stared at him. If he knew what this meant, that meant he'd hid something from her. That never boded well for Amycus. She utterly ignored Lucius for a minute, making sure Ammycus realized the moment she thought he knew something she didn't he'd be very unhappy.
Then she turned to look at Lucius, her posture a whole world of different, her head was up, her eyes were still narrowed. One leg crossed over the other. The one foot on the floor was balanced on her toes. She'd turned her attention from her twin and given it wholly to Lucius. "Warnings. Words." she waved her hand lightly. "What are you up to, Lucius?" she said with a calculating tone of voice. She was by no means dumb - in fact she was rather intelligent - and her mind was already spinning on ideas.