In this newest installment in Danneberg's series following Mrs. Hartwell's elementary school class, other staff members must step in when Mrs. H is ill.It's a teacher's worst nightmare-feeling awful, you call in sick, relying on your emergency sub plans to get your class through the day…but the substitute fails to show! Various staffers fill in for the beloved teacher, but none quite fill her shoes, as her students point out in messages sent over the Homeroom Hub. The gym teacher starts the day with loud music and exercise instead of having the kids do their morning jobs, and the math teacher fails to read a Junie B. Jones book aloud with multiple character voices. Alternating or facing pages show that Mrs. Hartwell isn't getting the kids' messages. Instead, she's taking care of herself and gradually starting to feel better, many of her activities matching the things going on in the class (they watch a penguin documentary; she watches dog and cat videos). When Mrs. Hartwell finally looks at her messages, she has 126, and she knows just what to do with her class the next day. Details in the watercolor, dye, and India ink illustrations will keep readers poring over them; the children's facial expressions are an especial delight. Mrs. Hartwell has light skin; students and other staff are diverse.A lighthearted look at an increasingly common scenario. (Picture book. 4-8)