From the back of the book:
"Although the Federation and the Gorn Alliance have concluded a treaty, a band of renegade Gorn ships have been raiding Federation shipping. This threatens to jeopardize the peace. The Gorn have told Star Fleet the location of the planet where the renegades have their base. Your destroyer, the USS Hastings, has been dispatched to carry a Gorn Ambassador to meet with the renegades. It seems like a normal mission, but the Ambassador turns out to be none other than the Gorn Captain who fought with Capt. James T. Kirk of the Enterprise. He brings aboard with him a squad of 'bodyguards.' Your Security chief senses that something isn't quite right...
Recommended for up to 9 players. Possible pre-generated PCs and vessel details (including deck plans) included."