Ghost Town at Sundown: Split the Wind

OK, so they finally reached the rustlers. Annie’s staying with the colt while Jack and Slim are confronting the rustlers.
When Slim’s like “OK, here’s the plan,” Annie’s like “OK, cool,” but Jack’s like “wIt, what?”
Now Slim’s like “this is far enough for you,” and Jack still has no idea what’s going on.
Oh, fun. Slim’s got the horses, but now the rustlers are shooting.
So, like, a ghost or something is distracting the rustlers?

Ghost Town at Sundown: Slim

OK, so this is the guy who initially herded the mustangs, and the rustlers stole all the horses.
So, this dude’s called Slim, and he decided Jack’s Shorty and Annie’s Smiley.
“How’d you two get here?” “Uh… a stagecoach… that we accidentally told to go to the wrong place…”
Sure, Jack, confronting the rustlers could be dangerous, but this is a kids’ book. Nothing bad’ll happen to you guys. Listen to Annie. That’s how you’ll find the riddle answer.
OK, yep. Time to go track down the rustlers.

So, apparently these horses are wild mustangs that the thieves or rustlers or whoever caught.
Of course Annie already figured out how to handle the colt before Jack could look it up because she’s great with animals.
Seriously, Jack. Listen to Annie. Reuniting the colt with his mom will help you find the answer to the riddle.
OK, who’s this new dude, and why does he think Jack and Annie are the horse thieves?

Oh, wow, so the town is a ghost town already? Even though they just traveled to the past? Must not be much silver or gold around there anymore…
Not sure on this riddle. I have an idea, but less than I did last time.
OK, so it was the river that dried up and everyone left.
And there’s more of the rabbits Morgan sent.
And there’s rattlesnakes everywhere.
OK, so there’s a calendar in the general store from 1878. Two years before the town was abandoned, apparently?
And now they’re trying on some cowboy outfits.
OK, but who’s playing the piano in the middle of a ghost town?

OK, so, Annie’s like “hey, that rabbit looks funny. Maybe we should go see if Morgan is telling us to go to the treehouse again.”
So yeah, Morgan’s there.
And now she’s sending Jack and Annie to the Wild West.

And now they’re back home.
OK, what? This one time, the treehouse forgot to use its auto-dry feature on the kids…
At least their shoes aren’t wet…

And now they’re back at the reef.
So Jack and Annie were accidentally racing each other when they were still swimming on their own because they wanted to get back to the reef and not get caught by the shark.
OK, so Jack’s backpack was not waterproof at all.
And the riddle answer is an oyster with a pearl in it.

OK, so the fin that’s following them is either really bad if it’s the shark and really good if it’s the dolphins…
Oh, fun. The reef is not as close as they thought.
And now they’re getting worn out.
Oh, OK. Looks like the dolphins are giving them a ride.

And they barely made it to the surface again, but the sub is leaking faster now.
The sub just died completely and the shark is still out there. Their swim lessons they had before going to the ice age would help, especially since they’re so close to the reef.
OK, something I’m wondering now: how waterproof is Jack’s backpack?