This is an expansion set for the TWERPS Game System.
one of the core rules publications is required
TWERPS Basic Rules (1st Edition) or
TWERPS Basic Rules (2nd Edition)
Your characters become intrepid investigators into the Unknown, the Unseen, the Unsure, and the Unbelievable, as special ops of the Top Hush Explorations (T.H.E) Agency.