Rad and Crayton - the same yet different. They meet as often as possible throughout the year to be together. Christmastime is particularly special; it's when they celebrate their bonding. Mermen, one born in the south Caribbean sea, the other from the frozen waters surrounding Iceland--neither can exist for long in the other's climate.
Rad returns to his summer home in Pennsylvania, determined it will be the last time. The cold has taken a deadly toll on him. Cray can go no farther south, so they will have to give up their bonding celebration, and the Christmas holiday together.
Cray discovers a way to defeat Mother Nature, but it may already be too late.