Five Run Away Together by Enid Blyton
Published June 29, 2020

Third in the Famous Five series, and this time the gang are very much left to fend for themselves. When Aunt and Uncle have to go away for illness, the crew find themselves at the mercy of some very unscrupulous fill-in housekeepers. It does make me wonder how much screening Uncle Quentin does on his staff, with these guys and with the rogue tutor from the previous book.