Next week's 'Pretty Little Liars' is an all-new episode with a brand-new concept that takes place entirely inside Spencer's head. That's right, things take a strange turn for our Liars in 'Shadow Play,' which will air in black and white with a 1940s noir theme.

Keep reading to find out spoilers about what will happen in the episode.

As the synopsis explains of the intriguing episode:

Spencer’s numerous sleepless nights with the help of prescription pills start to take a toll on her as her hunt for Ali and much needed answers continues.

As she pours over newly acquired information, her world view takes a black and white turn. Now teleported into the world of 1940’s Film Noir, Spencer tries to come up with the answers she and her friends have been desperately looking for.

According to Zap2It -- who have already seen episode 4x19 -- it will be chock-full of some Emily and Paige action, Alison will take center stage throughout the episode and that missing diary makes its return with some very important information.

And since this is a noir-themed episode there is plenty occurring in the shadows, including one mysterious figure stalking about in the promo (above) who may or may not be Ezra.

So the question remains: Are the events in the episode actually happening, and Spencer's tired brain is giving them a noir spin, or is this entirely a paranoid delusion taking place completely in Spencer's mind?

Tune into ABC Family at 8PM ET next Tuesday, Feb. 11, and we can all find out together.