Foster is only interested in the Rose. That's what the Ringmaster wants, so it's what he wants. He doesn't care about anything else, and his assumption is that if the bicorn servant was allowed here, then the Rose will not be.

He is, however, very aware of LeFlamme's warning about magic. He is so intent on keeping his hands--er, paws--to himself that he ends up agitatedly digging his claws into his hair instead. The sparrow is also in his hair, but in a much less restless way.

If anyone else intends to linger, he will look over the book shelves, doing his best to read the spines of what books he can see but growing increasingly impatient to move on.