Pout-Pout goes off the deep end.Plainly afflicted with anger issues, Mr. Fish leverages a broken knickknack, difficulty finding glue, and the mild reactions of his neighbors to his plight into a towering, out-of-control tantrum. Mrs. Squid offers a tried-and-true (though, at least for a fish, physically impossible) counterstrategy: "To get started, simply breathe. / Then slowly count from one to ten / To counteract the seethe." Miss Shimmer, another fish, suggests using his words to talk out his feelings…which he does (though only in the pictures, as Diesen declines to use her words to describe what he actually says). Finally, "with words and self-compassion / I bring anger to a stop," and once he's gotten his "grrrrr" out, the glue even turns up so that in no time fish and fracture are both "good as new." Unlike the "seethe" in Molly Bang's When Sophie Gets Angry-Really, Really Angry… (1999) or Polly Dunbar's Red Red Red (2020), the rage here comes across as manufactured rather than genuine-and the coping techniques are more described in general terms than actually demonstrated. Hanna's cartoon cast of fancifully colored deep-sea denizens is as googly-eyed as ever. He adds some amusing details, as with the labels on Mr. Fish's storage bins ("Might Need Someday" and "Not Sure will look later"), but the souvenir from "Machoo Poochy" is an unfortunate choice. (This book was reviewed digitally with 10-by-20-inch double-page spreads viewed at 75% of actual size.)An undistinguished addition to the infuriatingly overstuffed shelves of anger-management treatises. (Picture book. 6-8)