Olivia and her complicated little sister Nellie have lost their mother, and their salesman father has to leave them with their Great Aunt Minty while he travels. 5 year old Nellie is coping with the loss by hedging herself around with rules and obsessive behaviours, which Olivia has to safeguard and explain. Frail old Minty gives them the run of her overgrown garden and overloaded bookshelves, but otherwise stands back.
When Minty digs up a tiny blue teacup, and Olivia finds a story of children under enchantment in a garden like their own - a story written by a former owner of the house - Nellie sets out to find all the buried cups, and free the children trapped as flowers.
Overall, this was quite good. Lisle does a good job, within a short book, of portraying children suffering loss in different ways. As an adult reader, I could see the ending coming, but it didn't feel wrenched into shape. If I'd read this as a child, I would have loved it for the setting (overgrown garden, house full of books, eccentric old lady) though I might have been disappointed that the magic wasn't overt.