Doctor Who Falls the Shadow by Daniel O'Mahony

This lengthy text appears to be from a Doctor Who novel, specifically "Falls the Shadow" by Daniel O'Mahony, which is part of the New Adventures series. The narrative centers around several characters, including the Doctor's companions Ace and Bernice Summerfield, and features elements like the TARDIS malfunctioning, a creepy house with strange inhabitants and unsettling phenomena, and the mysterious, antagonistic entities named Gabriel and Tanith. The plot involves characters being trapped, subjected to psychological manipulation and physical dangers, and grappling with unsettling revelations about reality and the nature of the house itself. There's also a significant focus on the city of Cathedral and its creation and control by a being known as the grey man.