AN: I don't own Teen Wolf.
Something Wicked This Way Comes
He told Stiles to believe; to imagine the Mountain Ash working and he knew that if the boy did as he was told, that everything would work. There would be enough Mountain Ash, they would trap the Kanima (the poor Whittemore boy) and its Master, and Derek and his pack would finally be able to save the Kanima from its Master. Jackson would then be able to transform into a wolf, join Derek's pack, gain the family he's always wanted, and then the entire pack would be able to weather the storm coming.
But it all depended on Stiles.
Stiles who had lost his mother very young and wasn't able to hear about his heritage, about what gifts (he would soon discover he had) he inherited, and what his place is in the pack. But, because of his mother dying while he was still a child, Stiles is pessimistic. He doesn't believe in magic or the impossibility of all emcompasing happiness that radiated off his mother every day of her life.
Honestly, Deaton was worried.
He's Seen many things; different outcomes and paths that the future could take, but the one he's Seen more recently, the one he wants to happen so badly, involves Stiles. Stiles discovering and accepting his power; working with Derek, helping Derek, healing Derek and helping him let go of his baggage so he can move on and become the Alpha he was destined to be.
If the boy thought that he was under a lot of pressure with the Mountain Ash, Deaton couldn't wait to see how he'd react to being told that he was the only one capable of… well, that might not happen anyway. He shouldn't dwell on something that was only a Glimpse, but still. The boy needed to prepare himself for things to come.
But things are already progressing. Scott has joined Derek's pack, Derek is beginning to truly care for the others in his pack, Scott is beginning to bond with the pack, Stiles has (finally) tapped into his power, Isaac has made a healthy familial connection with Scott, Erica is learning to trust others, Allison has begun her own journey with her family and is thinking about the Choice she will soon have to make, Lydia has discovered her connection to Peter Hale and her power, and the connection between Stiles and Derek has made deep roots. The two have saved each other numerous times, often putting themselves in danger to protect the other, the unwavering trust Deaton Saw was forming.
It will take time, but they'll all get there.
He believes in them.
And if they begin to stray from what he believes will help them move to the path he's Seen, well, he'll give hints.
Like maybe the Kanima isn't afraid of water, maybe its Master is…
But that's just a thought from an old veterinarian.
So, when his daughter comes in, wary of his trust in this group of misfit teenagers (especially abou Lydia and the pack's ability to help the girl) with so much power and promise, he tells her that he trusts them. They'll be able to do all the wonderful things he's Seen, no doubt about it.
As for telling them about the problems coming ahead, well, he's not some immortal Seer now is he?
(Anyways, telling them would be against the Rules.)
No, they'll just have to learn along the way.
Besides, he believes in them; after all, he's Seen them do it before.