Mermaids of Ganymede

Trapped at the bottom of Ganymede's ocean, beneath a thick layer of ice, your survey ship has crash landed. Your crew has begun to see things swimming out there in the dark, and no one has ever made if off Ganymede alive. What will you gamble with to save your crew? Will you become a friend of mermaids, or will you seek out other powers along the ocean floor? Dark secrets await beneath the ice. How deep will you go?