Arcturus leant forward to take a closer look as the box was opened. Sirius, mirroring him, did just the same, and while the older wizard simply smiled appreciatively at the two little bottles, the younger one looked almost amazed by them. 'Look at the colours!' he exclaimed, picking up one and then the other, and marvelling at the interesting shades in each.
'Yes, they're very special,' said Arcturus warmly. 'Are you going to try the red one?'
Sirius tried to open the little bottle he was holding, but found it too difficult, and handed it over to Arcturus to do for him, which he did. 'Drink it all at once,' he advised. There was only a small amount, but Arcturus didn't know how it might taste, and they didn't need an argument over finishing it.
He needn't have worried. The little boy drained the shimmering liquid, and then looked back at the other two with a grin. 'It's strawberry, Mr O'Hara! Did you remember that was my favourite? What does the potion do?' Someone older than him might have asked that question first, but Sirius was still young enough to trust that the adults around him knew what was best.