Once you’ve tapped the tree, Maurice attacks you (if he’s here)- and what’s more, spriggans appear throughout the cave and attack not only you and any followers you brought in, but also the two pilgrims who were living in the sanctuary as well! Oops. One spriggan appears with you up at the tree, a second on the path leading down from the Eldergleam, and a third spriggan and a larger, nastier Spriggan Matron appear in the main part of the chamber, killing Asta and Sond (with some difficulty). Maurice is easy to handle, not wearing any armor and having only a two-handed weapon, but the spriggans are spriggans and like to turn semi-invisible. Using enchanted weapons can alleviate this some, causing a glow around their bodies dependant on the enchantment that doesn’t fade out when the spriggan do.
Either way things have gone, you got what you came for and it’s time to head back to Whiterun.
Returning to Danica is pretty simple and straight-forwards. If you have the sap, she thanks you and states she will use it to repair the Gildergreen. If you bring a sapling instead, she is suitably surprised, but still thankful- and declares her intent to plant the new tree in place of the failing Gildergreen. After this, you are on friendly terms with her, and if you need training in Restoration, she is a Master-level trainer for the skill, so this is also helpful.
As time passes, you will be able to see the effects of this quest in Whiterun- either the Gildergreen will gradually return to leafing and flowering, or the tree will be replaced entirely with the sapling, which grows a little, but not much (no matter how long you spend gadding about the land of Skyrim). Either way, the barren scraggly pale tree in the middle of the channels leading down from Dragonsreach will be replaced by a sight of pale pink leaves and some slightly fuzzy light in the area.
