How did Julia and Quentin return in the middle of The Magician King?

Question

I've been trying to figure this out, but I must have missed some little key detail. Here's what I know for sure.

Quentin and Julia are traveling through Fillory, exploring the islands. By the power of the magic keys, they accidentally return to Earth. After 3 days of trying to get back, they finally end up at the place where people were first able to go to Fillory, and somehow after a whole day of searching end up back at Fillory, first trying each of the methods outlined in the books for entering the place.

Thanks for the help!

Answer 1

They end up going back to the Chatwin's house where they spend the night...

Playing games with a young boy and getting very drunk... After a bout of the bed spins they find themselves back in Fillory...

The scene illustrates two points: Quentin has hit rock bottom, he finally gives up his childish need to return to Fillory and begins to imagine life as an adult, with a wife and family, in this world. Firmly planted back on Earth, playing games with a little boy, Quentin and his friends recapture the childlike (innocence?) magic that initially drew them to Fillory...