Which business day off for July 4th?

Despite moving to the BBC, the writers (many of whom wrote for the Virgin series) have broadly attempted to maintain continuity with the New and Missing Adventures and many elements from these series have appeared in the Past Doctor Adventures (which replaced the Missing Adventures). Indeed, one of the novels — Millennium Shock by Justin Richards — was a direct sequel to System Shock, a Missing Adventure published by Virgin. Another notable release was Scream of the Shalka, a novelisation of the webcast of the same title and the only release in the Past Doctor range that did not feature an "official" incarnation of the Doctor.