FOX has announced it will air the first-ever extended-length episode of Family Guy with limited commercial interruptions this spring.

The special episode, “Send in Stewie, Please,” focus on a troubled Stewie and feature a guest appearance by Ian McKellen (The Lord of the Rings).Here’s what we know so far about the episode, Stewie gets sent to the office of his school’s child psychologist, Dr. Cecil Pritchfield (McKellen), after he pushes a classmate. In the pychologist session, Stewie makes a number of personal revelations about himself. The episode will air March 11.

This news breaks as FOX preps for the largest milestone of all as Family Guy will pass 300 episodes as it enters its 16th season. That episode, “Dog Bites Bear,” is set to air on Jan. 14.