Of course it was less than legal. Shura doesn't doubt that Billie probably used less than legal methods of obtaining the books from the black market bookseller.

The smaller dragonet either doesn't notice her stalker or doesn't care. There's stuff to inspect! She knows things happen during the day while she's locked up in her pen, but she can't see anything, so she obviously has to make sure that nothing is out of place when she's finally free of her prison. If Red doesn't act quick, she'll eventually turn around and see him, but if he takes the chance, he'll get a good opportunity to pounce. Aconite's going to put up a much bigger fight than Alistair, but that's most things that aren't Strange's dragon.

In the meanwhile, Shura keeps half an eye on the dragons, reaching for the bottle and examining the label. "This your souvenir?"