Home › The Draco Tavern › The Missing Mass T The Missing Mass by Larry Niven · Book 15 of The Draco Tavern Buy on Amazon About “The Missing Mass” The Missing Mass is a book by Larry Niven. It is book 15 of the series The Draco Tavern. ← Ssoroghod's People All The Draco Tavern books in order The Convergence of the Old Mind →