Mrs. Peloki's class play Book

Something definitely happened with this last book in the series: just looking at cover art leads me to believe there was a switch in publishers, their illustrator was lost, or there was a drastic shift in marketing strategy (perhaps all?). One edition has a black cover reading Mrs. Harris Goes to Moscow in red lettering, like some dramatic murder mystery/thriller. It's simply not the same darling presentation. Funny, though. My first impression was "What on earth happened in Moscow, Mrs. 'Arris!?"
Overall, the story is still funny, but just doesn't have the same sparkle as the previous installments. I'd focus on Mrs. 'Arris Goes to Paris, Mrs. 'Arris Goes To Parliament, and Mrs. 'Arris Goes to New York, with the first two being my favorites.