Chapter 6: Ready, set ... BOOM!
Back to Rosella and the two King Otars. One of them's a fake, obviously. Look at the magic wand with the eye thing. Turn it so you can see the top -- you'll see a 'T'. Turn it around again so you can see the handle and click on it. Look at the top again and you should now see an 'F'. When the fake troll king is thrown against the wall, click the wand on him to change him back to his rightful form. Lo and behold, it's Edgar!! (You know, the ugly little man you rescued from Lolotte?) Malicia will appear, zap King Otar, make Edgar fly out of the room and imprison you inside the volcano that's about to erupt! Things are not looking too good for the Princess of Daventry.
Still in the cut-scene, we go back to Valanice and see her get picked up by a cloaked figure riding what appears to be Count Tsepish's horse. We see Rosella again, with the lava coming closer, then Lord Oberon, Lady Titania and Lady Maab on top of the volcano, putting a magic web over the top in the hopes of keeping it from exploding.
Back to Rosella and you'll have control. Dig your way out by using the shovel on the wall just to your right. Valanice and the cloaked figure get closer, opening the entrance that was sealed after Rosella was pulled up just in time. Back to Rosella inside the Vulcanix underground. Go left. Use the shovel on the big rock to loosen it, then climb up it and pick the flower. Open the door (left eye, right eye, nose). Plug the device you found at Malicia's into the socket and use the flower on King Otar to wake him. He'll stop the volcano and there'll be a reunion sequence -- first Rosella and Valanice, then Rosella and Edgar are reunited. Unfortunately, Malicia appears to mess things up. She'll zap Edgar. Quickly take the device from the socket and use it first on Malicia, then Cuddles, the dog. Give Edgar the life you got when you rescued the cat and watch the closing sequence in which you find out Edgar is Oberon and Titania's son and Malicia is Titania's sister (and they're starting over to see that Titania can't make Malicia a nicer person). Finally, Edgar takes Rosella to see what she came for in the first place -- the sights of Etheria. And there, Edgar tells Rosella he really did fall in love with her when she arrived at Lolotte's castle. He asks for the honour of courting her ... she says yes, and there's happy endings all round.
You've just completed Chapter 6 of King's Quest VII! Congratulations! You've completed the game!