Journey to the Living Planet! It's Lunella Lafayette's biggest adventure yet as a voice from the cosmos beckons her and Devil Dinosaur on a truly fantastic voyage — an Ego trip, if you will! Are you ready for Moon Girl to meet…Girl-Moon? Lunella isn't just smart, she's the smartest person on Earth — but what good is that when the problems she faces are intergalactic? And if our incredible adventurers make it back to Earth, they might find things a little different than they remember. What happened to Yancy Street? And who are Devil Girl and Moon Dinosaur?! And when the duo is thrown through time, the era they arrive in could give Devil the hardest choice of all — and leave Moon Girl scouring the Marvel Universe for a new partner!