Megan 'Mary Hightower' Mcgill is a 15-year-old self-proclaimed expert on Everlost. She has written many books on living in the world between life and death, and encourages Afterlights to accept Everlost and stop moving on. She also thinks of herself as the mother of the many children stuck in this world, being one of the oldest inhabitants at fifteen. She will do anything to keep the "lost" Afterlights in Everlost.

Initially a welcoming and kind character, Mary is revealed to have a lunatic plan of destroying the world and bringing the children into Everlost to "save" them. It is revealed in Everfound that she has been ordering the deaths of children in the living world via skinjacking. At the end of Everfound Mary seals herself in an old refrigerator and sinks to the center of the earth.