The Book of Dares for Lost Friends by Jane Kelly.
Best friends, Val and Lanora, meet in Central Park to plan their entrance into M.S. 10. Lanora has plans that don't include Val. Lanora decides to use middle school as a chance to re-invent herself. (My hopes were on the high side.) She intends to fill Val in on what is going on, eventually. There is a road paved with good intentions.
Val, in the meantime, has plenty to do while she misses Lanora. She follows the park's feral cat to a dusty antiques store, owned by an old coot and staffed by an odd young boy. She plays soccer - constantly and well. She joins a group of word obsessed self proclaimed outsiders.
When Lanora's plan leads her off the straight and narrow, Val tries to find a way to save her old friend. With the Book of Dares for Lost Friends, that strange boy, a pair of feathered wings and a midnight excursion, Val tries to bring the old Lanora back.
A great cast of characters, a hint of magic, superstition and the setting of a vibrant city add up to a suspenseful middle grade read. Readers will moan in disappointment and lean forward in hope as these kids muddle through adjusting to a new school and family drama. Questions remain about some of the characters. So maybe??