For "The Source," you will have to choose between Shani and Triss at the end. The one you don't choose will be mad at you, but will still talk to you if she's involved in a quest. So it's not a big deal to do this early.
For "Dandelion's Lute," he'll disappear from the New Narakort Inn if you haven't finished "The Source." After you've completed "The Source," he'll be back at the Inn.
You can remain Neutral if you pick up both "Echoes of Yesterday" from Yaevinn in the Druid Camp and "Six Feet Under" from Siegfried at the same time, and complete them early.
Advance "Beauty and the Beast" to a point. When you run out of side quests, do "A Posh Reception" and other main quests until you learn the identity of the wherewolf, then you can complete that quest.
"The Archespore Contract" you'll turn in to Jethro, and he'll start a main quest when you do, if Leuvaarden hasn't sent you to him already. All the other Contracts you'll turn into Velerad, but he won't accept them until you've completed the main quest "Gold Rush," which will trigger after "Lock and Key" (I think). The side you choose during "Gold Rush" will affect which side is available to choose at the end of the next chapter, between Neutral and the side you choose now.
Once everything is wrapped up, Leuvaarden will ask you to choose help between Yaevinn and Siegfried. The choice won't affect your overall Neutrality. Once you have one of them on your side, return to Leuvaarden, and Triss will teleport you to a cave. Meet up with your backup and then kill the mage off to the side (to the right, as your partner says). Grab the stone off the pedestal, then go to the opposite side of the cave to activate a portal, which will bring in more forces from your chosen side.
Kill all of the Salamander forces, then approach the Professor and Azar Javed for a conversation. (I've found a crash bug that occurs if you wait too long and/or instead attack the salamanders who later appear from the part of the cave you came from.) After another cutscene, chase the Professor down the tunnel and attack him. Eventually he ports you to another cave, where the kikimore queen kills him. If you approach her, or she reaches you, you'll die instantly. Instead, run away from her, and arm the Aard Sign. Geralt will say something about the supports, so aim at them and unleash Aard to temporarily halt the queen. Run past all the other kikimores, as you don't have time to fight them. Collapse a couple more supports, and eventually the cave will collapse on the queen.
Loot the queen, and a previously blocked section of tunnel will open up. Go out for a conversation with Adda, and you'll wind up in Chapter IV.
last modified 19 July 2017