De Vigan has created the most wonderful character in Lou Bertignac. She's a thirteen-year-old prodigy who conducts interesting investigative experiments (trying to find out why all frozen packaged food tastes the same, how watertight various containers are, to understand how the inspectors know if a metro ticket has been validated or not), finds her french classes so very interesting, quietly loves Lucas - the seventeen-year-old class bad boy (he was held back, she skipped a class or two) and who spends her afternoons at Austerlitz train station watching people come and go so she doesn't have to go home to her depressed mother and distraught father.
At the train station Lou meets No, a young homeless girl, and is drawn to her. Lou meets her often at cafes after school and No, knocking back vodkas, tells her about her life on the street. Lou's going to use the information for a dreaded school presentation. She's chosen the topic of life on the street for French women. When No goes missing Lou is frantic, she feels like she has failed No, and she travels through the seedier parts of Paris in order to find the homeless girl; Lou wants to give No a family and love. Then there is the chance that Lou's family can also be healed through helping No.
There is some beautiful writing here that tugged at my heartstrings:
"In the class photo...I'm up the front, where they put the smallest ones. Above me, up at the top, is Lucas, looking sullen. If you allow that a single straight line can be drawn between any two points, one day I'm going to draw a line from him to me or me to him." (p.13)
The story is complex but simple at the same time. Similarly the language is effortlessly sophisticated and philosophical topics are broached straightforwardly. I was on the edge of my seat, unable to totally put my trust in No (unlike Lou, for the most part) but desperate to be there for the ride. It's magnificent - for children and adults alike.