Parallels

"Reney woke from what felt like a light sleep - but when she looked out of her window, she realised something was different. She wasn't in her bedroom. She wasn't even in her house - or her parents' house, rather. This was her workplace: Ruggle's book-mending shop. Ruggle was a goblin, but he was nowhere to be seen - and this was not surprising: when Reney looked at the great clock that hung on one of the walls, it told her that it was one hour past closing time. Reney frowned - she had somehow slept through the day without even remembering having fallen asleep!- When suddenly she knew what it meant."

After having returned from the Labyrinth, Sarah is determined to hate evil Jareth forever - and yet she can't stop being curious about and scared of him at the same time. Knowing that he can enter her world from the Labyrinth, Sarah starts looking for him - just to see if she could outwit him, if she could find him. But what she does indeed find is different to anything she expected.
At the same time in the Labyrinth, rumour spreads that the Goblin King has fallen in love with the last human girl whose sibling he had stolen. Trying to get his mind off Sarah, an incident takes him by surprise, proving that he has forgotten what it means that Labyrinth and Earth are parallel worlds.