From the back cover: "Terra Incognita is a roleplaying game of exploration, intrigue and mystery, featuring adventure-scholars whose exploits span the late Nineteenth and early Twentieth Centuries. Armed with extensive training, unpredictable technology, and unimpeachable discretion, society members ("Nags") travel to the Four Corners of the globe – exploring unknown lands, investigating mysteries, and uncovering ancient knowledge. The Society studies and catalog the information and artifacts so gleaned and sets about covering such things back up again if they deem the world is not yet ready for the knowledge or power that had lain hidden for so long."