 A wall separating the innocent from the guilty is perilously breached when ex-cons mistakenly steal radioactive cobalt, then abandon it. Thinking the cobalt container hides industrial diamonds, they open it in their front, an auto repair shop, endangering the neighborhood. As they lie low, before fleeing to Mexico, only the youngest of the trio is concerned about the neighbors, especially a female shopkeeper he cares for (Katharine Ross, The Graduate). Fear mounts, as the mechanic (Norman Fell, 3 s Company) who pried open the Pandora s box, grows ill, and the FBI tracks the radioactivity.