Prisoner of Ice

Prisoner of Ice (also Call of Cthulhu: Prisoner of Ice) is a 1995 computer game based on H. P. Lovecraft's Cthulhu Mythos, particularly At the Mountains of Madness. The game, like its predecessor Shadow of the Comet, is an adventure game.

In 1997, the game was released on Sega Saturn and PlayStation exclusively in Japan.

Plot
Prisoner of Ice takes place in August 1939, one month before World War II, primarily around Antarctica. It concerns a young American officer, Lt. Ryan, who has been assigned to a British submarine, the HMS Victoria, for special missions.

As the game begins, the submarine is fleeing the Antarctic after rescuing a Norwegian who has recently escaped from a secret German base in the Antarctic (it is later revealed that the base is built atop the Ancient Ruins mentioned in At the Mountains of Madness). Along with the Norwegian, the sub has picked up two "top secret" crates, stolen from the Nazi base.

Late in the game, Ryan meets John Parker, the central character from Shadow of the Comet, and reveals the links between the two games. Narackamous, the main antagonist of Shadow of the Comet, also returns. He appears to have returned to life after being seemingly killed by Parker in Shadow of the Comet.

The game has a choice of endings, though there is little difference between them.