The first of the five films where Bill Elliott played a detective lieutenant in the L.A Sheriff's department, Dial Red "O" (the correct title with the number 0 (zero), as on a telephone dial, shown in ") opens with war-torn veteran Ralph Wyatt getting word that his wife is divorcing him, and he flees the psychiatric ward of the veteran's hospital, wanting to talk to her. His escape touches off an all-out manhunt, led by Lieutenant Andy Flynn of the sheriff's department.

In post-apocalyptic New York, three tribes of survivors (the Norms, the Mutates and the Upriver People) vie for the right to exist. When the treacherous Upriver People attack the Norms, kill their chief and take their people captive, two Norm refugee men must find a way to ally with the Mutates, who have previously kidnapped Norm women in an effort to reproduce healthy children, to rout the Uprivers, who also seek to kill off the Mutates.

A gang of bank robbers is pursued by an insurance investigator.

A 17th-century Caribbean port rumored to have frequented by pirates rises from the ocean floor, where it came to rest after an earthquake many years before. A scientist wants to study it, some thugs want the treasure alleged to be stored there, a bunch of mutated giant crabs living there attack them all.

Police sergeants Johnson and McManus take on Los Angeles confidence tricksters. Con man Tony Wells, lining up rich widow Jessica Royce as his latest mark, sets up a false paranormal society with other charlatans to convince the credulous Jessica that her late son is speaking to her through their sham seances. When the plan leads to murder, Johnson and McManus must bring the group down before they kill again.

When a scheming fortune hunter finds his rich wife is not going to die as expected, he and his lover make other plans to get her millions.