Doomwalk is the fourth book in the Bloodsword gamebook collection. This is arguably the best and most memorable of the Bloodsword series, due to the underworld location and suitably dark and disturbing atmosphere. It would have served as a worthy ending to the series The only drawback from the series was the complex combat system. But that is easily solvable, just don't bother with it. The book stands up on the quality of the writing alone.
I owned many gamebook series back in the day but culled most of them from my collection. Bloodsword is the collection I regret getting rid of the most, hence me purchasing it again. On a more positive note, at least the authors got paid twice over. There are probably around ten stand out gamebook series in total, this being one of them. One or both of the authors being involved in three or four of the others (more if you allow for Jamie Thomson's cameo role in book 5). But then you probably know that already if you're reading this.