 Alex Murry's interest in the space/time continuum, which led to the events of "A Wrinkle in Time", is revisited in depth here.Kate Murry comments on her daughter Meg having had too low an opinion of herself, as seen in "A Wrinkle in Time" and "A Wind in the Door"; Kate's research in subcellular biology, a major component of "A Wind in the Door", is also mentioned repeatedly.The snake Louise the Larger and her human counterpart, Dr. Louise Colubra, both introduced in "A Wind in the Door", return in "An Acceptable Time".