Doctor Who is heading into the woods during "In the Forest of the Night."

'Doctor Who' Finale To Feature 'The Darkest Day, The Blackest Hour,' Steven Moffat Teases Shocking Episode

Unfortunately, Twelve and Clara won't be jumping into the Sondheim musical. Instead, the pair will enter a brand new London - one that became engulfed in trees overnight. To make matters worse, a wolf will make a frightening appearance and Clara and Danny's will have a group of students keep out of its hungry jaws.

"A fairytale, but not in the sense that I've tended to write a fairytale," teased showrunner Steven Moffat, according to SFX (via CultBox). "Heartfelt, eloquent, quite, quite different."

'Doctor Who' Needs More Woman Writers? Neil Gaiman Talks Gender Imbalance

Check out a dialogue snippet from Doctor Who Magazine (via Doctor Who TV) below:

"THE DOCTOR: 'I'm afraid clever isn't much use against trees. They don't listen to reason. You can't lie to them. You can't plead with them. They have no moving parts, no circuits, no Wi-Fi. You wave your sonic screwdriver at them all you like and they just keep growing. This is a natural event.'
DANNY: 'How can it be natural for a tree to grow in a night?'
THE DOCTOR: 'Exactly what they said about the Ice Age. How can whole glaciers just pop up out of nowhere? They just did. That's how this planet grows - a series of catastrophes. The Ice Age is over. Welcome to the Tree Age.'"

Find out more when Doctor Who airs Saturdays on the BBC and BBC America. Click the video below to see a sneak peek for "In the Forest of the Night."