D&D 5E To Slay a Dragon, Act 2

First off: Is there really no prefix for this campaign? That sadens me

Now, we're about to head into act 2. The heroes have just returned to Hengistbury only to be told about the abduction, and in the next session we'll do the transition to act 2.
However, I can't for the life of me find and real hooks that would draw the party into trying to get the 4 items they are supposed to have before they attack the dragon in act 3. I imagine they would enter Blackford first, there should be a lot of obvious tension with the bandits ruling and all. But what would make the party go "oh yeah, we'll stick around here and fix this area, despite being tasked to kill the dragon and rescue Ariadne.

So, any have any idea how this was MEANT to be handled?

Yikes, it's been a long time since we wrote that. I'd actually have to look at it again to remind myself!

I think generally, the intention was to make it sandbox in an old-school way, so they *don't* have to do the various quests. They do them if they want to or if they feel it's right to. It's set up differently to a standard adventure in that it is very possible to meet the dragon unprepared.

Meh... somehow my response got lost.
The long and short of it: Me and my players love the campaign, act1 was a blast to play and run. I really dig act 2 as well, though I could do without all the (somewhat repetitive) "here's three ways for the party to solve this: Fight (run 3 xyz random encounters), talk (have them roll for ABC skill) sneak (have them roll for DEF skill)". I guess what that means is, this module is even more sandboxy, in that it gives the DM less concrete stuff to work with than act 1. I'll just have to grow as a DM.
I had already discovered the bit about the party being totally allowed to leave act 2 prematurely, and I love it. It makes sense in the feel of the campaign. It does, however, aggravate my problem with the "missing initial hook".

Nothing there to stop my players from going "Oh dear, stuff looks bleak here, and appears to get worse the closer we get to the mountain. We're tasked with killing the dragon and saving the maid. We were giving the magic sword of the Pempertons, what are we waiting for? ONWARD HO!" and just blast through straight to act 3, never even guessing that there is anything for them to do before they get to the mountain.

I have a thing or two that potentially could help me with this, I'll be doing a lot of winging it, but I'd feel better if I'd know what you guys where having in mind with this back when you wrote this module.