The Vanishing of Katharina Linden is one of those novels where the main character is a child (in this case, 11 years old), yet is not at all written for children. The story opens on a gruesome note (yet a little darkly humorous, for all that) as young Pia Kolvinbach's grandmother lights herself on fire and burns to death. The story becomes exaggerated, and Pia becomes known as the girl with the exploding grandmother.
Ostracized by the other children her age, Pia becomes friends with the other social outcast, Stefan, and the novel more-or-less chronicles their next year together. Although the novel is ostensibly a mystery, about the titular vanishing, I didn't find the mystery to be the main attraction. I'm not sure author Helen Grant did either; less than half of the novel is given over to it, and even there, we saw more of how the stress of a disappearing child plays out in the town, and not very much about solving the mystery.
Helen Grant weaves together legends from the town of BadMuensterEifel (where the novel is set); a good small-town setting; and the interesting characters of Pia herself, her family, and the town citizens into a compelling coming-of-age story. Really, the coming-of-age story is not a genre that typically interests me; for me, the exceptions all have some other interesting facets to recommend them. So it is here -- Grant is very good at placing Pia at a time when she still wants to believe in fairy stories, but is growing too old for them.