"I never said I'd help you out," Strange briefly reminds Billie. However, of course he is. Why wouldn't he? And so, he just continues talking like they're all under the assumption that he's going to help Billie out.

"It's no use searching for books about the dragons: I suspect they're mostly destroyed." Which Strange is obviously annoyed about. "Any books on sympathetic magic or mental communication could be useful. Likewise, there's a trinket that lets one see through their animas's eyes. If you can obtain one, I can study the magic on that."

There's a moment where Strange looks over at Billie, pausing as he debates whether to bring up the 'guess what, I can do necromancy' card or not. "Of course, there are other methods to ask dragons or dragonborn directly about how the connection works. But those methods would require a corpse."