Arctic

The Arctic is a polar region located at the northernmost part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, the United States (Alaska), Denmark (Greenland), Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost. The area can be defined as north of the Arctic Circle (66° 33'N), the approximate limit of the midnight sun and the polar night. Alternatively, it can be defined as the region where the average temperature for the warmest month (July) is below 10 °C (50 °F); the northernmost tree line roughly follows the isotherm at the boundary of this region.

Fantastic Four
500,000 years ago, an alien race known as the Flb'Dbi came to the planet Earth and landed in the Arctic. An exploratory expedition, they remained on the planet for several thousand years collecting data. A mysterious phenomena occurred that reversed the polarity of the entire planet, sending an electromagnetic wave that rendered their space vessel inert. Unable to power their ship's engines, they created plastoid drones to effect long-term repairs while the Flb'Dbi placed themselves into suspended animation until such time that they could leave. Half a million years later, the Flb'Dbi awakened, and found that the drones had erected a massive crystalline tower - the purpose of which was to reverse the Earth's polarity again so that they could leave. Their first attempt to accomplish this generated a second electromagnetic wave. The Fantastic Four went to investigate and were forced to do battle with the drones. The Invisible Girl met with the Flb'Dbi leader, Primus, who explained his position. The FF helped them to repair the ship so they could leave and the Thing destroyed the crystalline tower.