From publisher blurb:
Welcome to Volume X of the BX Game Options. This issue presents familiars and not-so-familiars as well as a themed tower map set that can be easily populated by an enterprising game master with suggestions for use.
While familiars are not unknown from various editions of BX themed games, the topic is covered with options in how the game master may wish to utilize them and the benefits they provide to those they become linked.
In regard to the not-so-familiars five new races are introduced simply known as the folk, anthropomorphic animals that may be easily mistaken for their were-beast counterparts. Rules presented can easily be used both as non-player characters and player characters with game master approval.
The Towers of the Spike introduces a set of towers set upon a lonely spire that conceals a gate to untold terrors below. Maps are included for all five floors of the towers with notes as to what may occupy them and suggestions as to how the towers can be implemented in any game adventure. The digital version will also include a PDF of just the maps as well.
For full transparency, it should be noted that this volume does refer to earlier volumes that have come before it.