Death in the Air - Shane Peacock
After losing his mother while solving a brutal murder, young Sherlock Holmes commits himself to fighting crime. While visiting his father at work, Sherlock watches a dangerous trapeze performance. When the troupe's star drops to his death, Sherlock notices something is amiss and realizes it was foul play.
Rex Zero: King of Nothing - Tim Wynne-Jones
In 1962 Ottawa, eleven-year-old Rex Norton-Norton faces several confusing mysteries, including his father's troubling secrets from World War II, the problems of a beautiful but unhappy woman named Natasha, what to do about his mean and vindictive teacher, and whether or not he should even be concerned about these things.
Drowned Wednesday - Garth Nix
Everyone is after Arthur Penhaligon including strange pirates, shadowy creatures, and Drowned Wednesday, whose gluttony threatens both her world and Arthur's.
Sir Thursday - Garth Nix
When Arthur is drafted into the Glorious Army of the Architect by Sir Thursday, he must survive basic training, avoid getting posted to the Front, and figure out how to free Part Four of the Will, while Leaf tries to banish Arthur's doppleganger on Earth.
Lady Friday - Garth Nix
Young Arthur Penhaligon must weigh an offer from Lady Friday that is either a cunning trap for the Rightful Heir or a golden opportunity that he must seize.
Superior Saturday - Garth Nix
Even as he grows stronger and closer to discovering the secret of his identity, Arthur must face further dangers and conflicts as he struggles to attain the Sixth Key from the powerful Saturday.