In Cold Fear the player takes on the role of Tom Hansen, a former soldier now in the employ of the United States Coast Guard who has been sent in to investigate a mysterious Russian whaler Eastern Spirit in the middle of the Bering strait. The beginning cut-scenes show a SEAL team under the orders of a CIA agent, identifying the ship and trying to discover its cargo. Unfortunately, the SEAL squad is slaughtered mercilessly by an unknown threat. CIA agent Bennett then orders any government vessel in the vicinity of the Russian boat to investigate, and it is Hansen's ship which responds. As Hansen, the player finds out that the boat is occupied by hostile Russian soldiers and by strange creatures, known as "exocells", that use humans and other life forms as hosts to feed on and to use as protection from the environment. These parasites are a threat to Hansen from inside and outside their host bodies. His investigation leads to the mystery of the ship and its lethal cargo as well as the unethical experiments which were being carried out aboard the ship.
Source: Wikipedia, "Cold Fear," available under the CC-BY-SA License.