In a letter dated 26 August 1991 Patrick Tilley confirmed that both the fans and publishers wanted additional novels to be published in the series and he was pursuing the matter, but only if he could "make it good enough.". Rumours circulated for several years that additional novels in the sequence were being written, reaching a height in 1999 when a seventh volume was listed for publication by several websites. Unsubstantiated rumours surfaced in 2001 that Book 7 would be called "Ghost Rider", and that one of the characters killed at the end of book 6 wasn't actually dead.