This marks the third film that William Goldman has adapted from a Stephen King  novel. The others were Hearts in Atlantis (2001) and Misery (1990).

The character of Colonel Kurtz in the novel was changed to Colonel Curtis for the movie so the audience wouldn't regard the name as being a reference to the Apocalypse Now (1979) character.

Stephen King  sold the movie rights for US $1.

There were many references to other Stephen King projects, such as: Misery (1990) (car wreck in the snow); Stand by Me (1986) (boyhood friends walking on railroad tracks); It (1990) (TV) (flashbacks showing growing friendships), etc. And of course the story taking place in Maine - Stephen King's State of birth.

Thomas Jane did the film because his mother, a big Stephen King fan, told him to.

Damian Lewis's alien character, Mr. Grey, alludes to a poem while talking to Jones. The poem referred to is Robert Frost's "Stopping by Woods on a Snowy Evening".

This was the story that Stephen King wrote while he recovered from his near fatal accident. The accident is reflected in the story, especially in a graphic scene in which a major character in run down by a vehicle.

Since it is well established in the movie that the alien species has been codenamed "Ripley", a reference to Sigourney Weaver's character in Alien (1979) it would also be safe to presume the Damian Lewis's character "Jonesy" is a reference to the cat from the same movie.

To portray Mr. Grey speaking through Jonesy, Damian Lewis did an impression of actor Malcolm McDowell.