Phantom of the Heart by Tammy Yourzek

In this, the concluding volume of the Reality Twist Series, Katie Martin ventures one last time into the diabolical video game that has caused her and her family so much heartbreak in the past. The reason for her third journey? Her brother Alex and her best friend Jessie have turned into automatons, their souls, or "specters," still trapped inside the game! Katie must track down the specters and return them to their proper owners, which will effectively shut down the game...