Invaders and protectors face off in the human digestive system.Pale-skinned, red-haired young Sophia's down for the count with a stomachache. Elcomb and Po offer readers an up-close look at the causes of-and solution to-her ailment. First, the members of the Diagnosis Detectives Agency are introduced: anthropomorphized T-cells, B-cells, monocytes, and neutrophils, the white cells that make up the body's immune system. Next, we meet the bacterial and viral opposition, led by evil Queen Tox, a menacing blue creature clad in a red crown and dress. All are nicknamed and profiled, but depicted realistically when it comes to unpacking their effects on the body. Most chapters detail the various causes of digestive distress, among them norovirus, food intolerance, and food poisoning, as well as symptoms such as diarrhea, fever, and vomiting. The book concludes by identifying the culprit in this case and describing Sophia's recovery. Relying on the conventions of detective procedure makes for a satisfying plot frame as suspects are listed (with accompanying "mug shots") and the outbreak solved. Po's artwork combines imagination with accuracy; the central players are portrayed both as they appear under a microscope and in their blobby, cartoonish forms. Insets allow readers to pinpoint the location of the actions, while larger images depict close-ups of the adversaries going at it. Age-appropriate art and science projects are interspersed, along with an "I spy" page.A STEAM winner, sure to inspire future physicians-and reassure young hypochondriacs.
