When Meg meets her father again for the first time since he disappeared, what does she have to do to help him escape?

Meg, Calvin, and the mind-controlled Charles Wallace find Mr. Murry imprisoned in a clear, circular column with invisible walls. To penetrate the walls and get to her father, Meg has to put on the glasses that Mrs. Who gave her. They allow her in, and once with her father, Meg gives him the glasses. He goes out of the column, then comes back, and holding her, they both escape.
Once outside of the column they have to resist IT's attempts at mind control. To do this, Meg, has to lean into her faults of anger, impatience, and stubbornness. Finally, Mr. Murry is able to tesser her, Calvin, and himself off the planet Camazotz, but Charles Wallace, unfortunately, is left behind in the grip of the evil IT.