Here There Be DragonsBook - 1993
Penetrating the cloud, the Starship crew is shocked to discover a world of knights and serfs lifted right out of Earth's Middle Ages. Ruthlessly exploiting the planet is a ring of intersellar trophy hunters preying on the immense, native dragon-lizards twentey-feet tall and armored like tanks.
Beaming down, an away team soon becomes embroiled in a web of intrigue and murder. Taken prisoner, Picard, Riker, Data and Ro must somehow escape and stop the hunters or face destruction from the hunters' weapon, based on an advanced technoloy capable of utterly annihilating the "Starship Enterprise .