When eleven-year-old Micah's grandfather goes missing, her instincts lead her to the off-limits Finch House, but when a boy named Theo invites her in, Micah realizes she cannot leave and must convince the house to let her go.

In her second year at Arcanum Training Institute, Ella grapples with fame, unearths a perilous school secret, and faces a mysterious magical illness outbreak, prompting her, alongside Brigit and Jason, to clear her name, while working tirelessly to safeguard the Marvellian realm from impending chaos.

After twelve-year-old Ellis's big break turns into his most embarrassing moment ever and his relationship with his dad and their cookie store starts to change, Ellis hatches plans to get his life back on track.