Tripod

Early in their adventure the players encountered a Martian Tripod in Siberia, though they had no idea of its actual origin. As far as they know, it could be an experimental German war-machine, while the locals were convinced it was the Hut of Baba Yaga walking around.

Later the players encountered more Tripods during an archeological exploration of the lost city of Atlantis. Atlantis was revealed to have been an ancient beacon a group of stranded Martian scouts had influenced a human tribe to build. Powered by seismic activity and sea-water the beacon was meant to transmit a signal to Mars, telling the planet's supercomputers that Earth was ripe for mass-emigration and to wake the hibernating Martian populace. But before the beacon had enough power, Atlantis began to sink. The Martians on Earth went into hibernation to wait for the system to re-charge on its own. They forcefully mutated the Atlanteans into fish-people to keep an eye on the machinery, but the Atlanteans became feral and forgot about how the machines worked. For 10,000 years Atlantis was left alone, until the players arrived with Captain Nemo and had to sort things out.