My party got to the Nameless Spire in The Hungry Storm. Upon arriving, they fought the hoarfrost spirits, the chardas, the wights, the frost phantoms, and finally the moonflower. After the moonflower took and cocooned Sandru, the party left the building. Now a new moonflower appears.
What are some interesting ways I could run their return to the spire to tackle entering and ascending the tower? I don't imagine that it's exactly how they left it, but hitting reset on the creatures doesn't seem entirely fair, either.
The PCs are ignoring the tower? The tower that's the source of the nasty storms blocking their way?
Maybe create a moonflower with a "homing sense" locked on Sandru's home, which is the caravan?