The Mystery of the Locked Room — Sheridan Winn

THE MYSTERY OF THE LOCKED ROOM is the 8th volume in Sheridan Winn's bestselling Sprite Sister series. The magical adventures of Flame, Marina, Ash and Ariel are aimed at readers aged 7-13 years and have sold 450,000 books.

Each of the four Sprite Sisters has a magic power related to one of the four elements; Fire, Water, Earth and Air.

Snow is about to fall at the end of the autumn term at Drysdale's School. Flame, now 15, is agonising over her relationship with Quinn, while Marina, 14, is busy rehearsing for her leading role in the school play. 

Late one afternoon, Ash's intuition is alerted by the curious behaviour of twin boys new to the senior school. She follows the twins to the headmaster's office, but they vanish into thin air. When the locked room is found ransacked, Ash is certain the twins are responsible - but how did they get in? Back at Sprite Towers, Ariel soon has a theory. 

The Sprite Sisters quickly realise the Treadwell twins are much more than they appear to be. When one of the sisters is hurt, and with havoc created at every turn, the Sprites must act quickly. But have they met their match in the twins with the beady black eyes and strangely pointed teeth? 

THE SPRITE SISTERS 
Four sisters 
Four elements 
Four powers