Note: "Black Maria" is the original title for the book later published as "Aunt Maria."
After her father is killed in a car accident, Nan and what's left of her family are invited to spend the school holiday with their paternal Aunt Maria. Nan thinks it's a bad idea to stay with her father's relatives, particularly the one who raised him, but her mother feels sorry for the helpless old woman and accepts. Far from being helpless, the aunt is ludicrously particular and demanding of the mom, adores Nan, and shows an instant (and mutually reciprocated) loathing for Nan's brother. But other than that everything is pretty dull (the vacation, not the story). And then Nan and her brother discover their father's car in a parking lot when it's supposed to have crashed into the ocean, an anonymous green ghost appears in a bedroom, and a lot of people seem obsessed with finding and/or hiding a small box. The children realize something very strange is afoot.
Nan's brother gets an idea as to what that could be, but he won't let Nan help him. And then he disappears, and their mother doesn't notice even when he's been gone for several days, and Aunt Maria takes a sudden keen interest in Nan's activities.
Nan wants to find out what's going on and get her family back to normal. To do that, she first must solve a mystery dating back to events twenty years before--a mystery for which she has precious few clues to go on. The townspeople won't help--they're either against her, or too afraid to fight what they know she's up against. And all the while she has to dodge around Aunt Maria's prying, meddling, seriously menacing curiosity.
It's all really quite fun. I particularly like the way Jones throws out clues that seem so slender they don't seem to be clues at all, puts Nan into truly dangerous situations (all the scarier for the fact that in a village full of people our heroine cannot appeal to *anybody* for help), makes the story seem like there is no way on earth it can ever work out--and then executes such a series of brilliant twists and startling turns that suddenly when you find everything has come out more or less right after all it's a real unexpected pleasure. The book by turns tragic, dark, exciting, dramatic, and funny (sometimes all at the same time). And yet everything is totally plausible and entertaining.
Nan is a quiet, intelligent heroine--she understands people, and is not impressed or fooled by appearances. As she works to save her brother and mother and maybe even a whole town (all the while tossing out funny, spot-on observations about the people she meets), there is always the unspoken acceptance in her mind that whatever happens, there can be no completely happy ending--only the right one. She's right, too, and I like her all the more for it.