A previously unknown immense cave system is discovered underneath Europe. It has been nicknamed "Terrarium" - in it animals have evolved into species unknown and strange to man. You are the head of a team of biologists set on an expedition to discover these new species within the caverns. You discover the cave by laying out tiles. Within the caves you can discover pieces of information on the animals (Mammals, Reptilians, Birds, Fish, Insects). Then you must study and construct the animal at your base camp. In the end you will have discovered new species. The explorer who has discovered more and rarer animals will gain the most prestige and win the game.