Asteroidea is about regeneration: personal, professional, cellular. As the novel opens, marine biologist Claire Holt is at a frustrating crossroads. Having spent her career experimenting on asteroidea, commonly called starfish, and trying, without success, to transfer their regenerative capabilities to mammals, she's grown frustrated and depressed. With her grants running dry, time running out, and her two grown daughters facing their own life changes, Claire feels defeated. To cope, she takes a journey back to her childhood home, only to discover several startling and destabilizing facts about her past. As she tries to handle the resulting intergenerational and emotional fall out, a graduate student arrives at her lab with a newly discovered, promising species of asteroidea. Juggling emotional and familial upheaval, as well as this fresh direction for her research challenges Claire to re-engage in both her work and in life.