This story is about a crusading scientist out to stop nuclear testing who is motivated by scientific fact, conscience and faith. Dr. Alex Carmody (Martin Sheen) is a physicist who becomes convinced that if the U.S. and the U.S.S.R. continue to test nuclear weapons, eventually one of these tests will set off an atomic chain reaction that will obliterate the world. Carmody travels to Portugal where he tries talks to one of the women who in 1911 saw a vision of the Virgin Mary that spoke to her and her two companions about the future. Carmody is certain that the Virgin Mary predicted the very chain reaction he and his co-worker Dr. Kenneth Parrish (Peter Firth) envision. Failing in his attempt to talk to the woman, Carmody then travels to Paris and elsewhere, warning Soviet and American officials that the tests they are planning should be cancelled before they become their last.

A priest secretly leads rebels in their struggle against the corrupt military dictatorship of the Central American country of Puerto Santo.

It was a brutal murder that sent deranged psychopath Martin Kagan to prison. It was a naive deputy warden that granted him a stay of execution. Now, the police department's tactical defence instructor, John Lomax, wants revenge for his beloved sister's death.

A young couple grieving the recent death of their daughter move to the countryside where they are haunted by their tragedy and a sinister darkness.