Hunter Moran Saves the Universe — Patricia Reilly Giff

Twins Hunter and Zack have a small problem to solve: they must save their town from a diabolical dentist who is planning to blow it to smithereens. But first they have to hold a funeral for an incriminating report card before it breaks their mother's heart, hide a cello that has been demolished, and keep their father from finding out what they did to his laptop. None of this is going to be easy with their busybody older sister, Linny, watching their every move; older brother, William, just waiting to get them in trouble; five-year-old brother, Steadman, tailing them; and baby Mary banging her spoon like a maniac so no one can think. Before the book is over, a vintage airplane, a hot air balloon, and a borrowed fire engine will all play parts in the unfolding mystery. This novel is filled with whimsical characters, lots of mischief, and plenty of heart.