Flyby

Once the tower has been cleared out, the party will be ready for a new direction. The miners will request that they escort them to town for safety's sake. After so many months living underground in forced labor, they are desperate to get to civilization. Even after they get to town, at least half of them will feel the need to continue upriver to Aron's Bowl on the first boat, concerned that Faring Ford is too remote and unsettled to provide adequate safety.
The Hardys are in particularly bad shape, living a desperate existence cut off from any humans, and forced to fend off natural predators and scrape by on the little they could find. They will need to spend 2-3 days at the Whisper Inn to regain their strength before continuing on to Aron's Bowl. With no money on them, they need to trade on their position for credit. They need to get back on track with their mine quickly, so they ask for an escort to Aron's Bowl in order to hire new miners to come back with them to the mine. Most of their miners will return after a month or two, but they need some time away.
Granak managed to escape the destruction of his forces at the mine, and retreated to his own lair. There is a call from the townsfolk to track him down and take him to task. The barkeep Carson, and Callie the innkeeper offer 50 gp each to you if you'll bring him back to justice.
While the Hardys are recuperating, and the miners are taking to the boat headed upriver, a sudden chill takes hold for everyone in the town. The party is standing in front of the Whisper Inn. Aware of the utter silence that has taken over the morning, the entire party looks around to see what might be the cause of the unease. Have everyone make a Perception check DC20 to notice something moving high above the town.
With a sudden rush that catches everyone by surprise that didn't notice the movement in the clouds, a giant, red-scaled form swoops down out of the sky with a terrible roar breathing fire at the party and the Inn before flying back up into the clouds. The party must make a successful DC21 Dexterity ST or take 18d6 damage from the fiery breath. The dragon will sweep overhead several more times, staying well out of reach. After a few minutes (when its breath recharges), it will actually land on the town square, using its frightful presence on everyone within 120'. If anyone tries attacking it, it will speak before breathing again.
"You dare to oppose me! I have tolerated enough aggression from you vermin crawling over my valley. The time has come to remind you of what fear is, and where you can find it." With that, the dragon rises into the air and breaths again on the warehouse and dock, then soars up into the sky and heads south toward Aron's Bowl and its lair in the mountains beyond.
This brief encounter is worth 3600 xp (20% of the dragon's total), and may spur them to start moving back upriver more quickly. If they decide to go after Granak Smith that is fine, but they should follow that by continuing upriver.