Newlyweds Don and Pat Carter are driving to New York City and have to stop in the town of Ridgeview, Ohio when their car breaks down. They get a tow to the mechanic, who says that their car will take four hours to arrive. Don is awaiting news of his promotion and is concerned although Pat assures him he has nothing to worry about. As they go to the nearby diner, a superstitious Don does "bread and butter" as they walk around a lamppost. They take a table at the diner and notice the "mystic seer" napkin holder on the table that gives out answers to yes-or-no questions. Don puts in a coin and asks if anything exciting ever happens in Ridgeview. The card the machine gives out seemingly answers his question, saying "It is quite possible."
They get their food and Don continues to ask the machine questions. When the machine says that it is assured Don will get his promotion, he decides to call the office in New York and they tell him he got the promotion to office manager. As they get their food, Don asks the machine if they'll leave in four hours, the machine gives out a card that ominously says they may never know. Don tries to determine why and it says they need to move soon. He then narrows it down to something happening at 3 p.m. Pat suggests they leave but Don delays until 3 p.m. As they walk back to the mechanic's, Pat insists the whole thing is coincidence but Don isn't convinced. Finally he apologizes for being so superstitious. However, as they cross a street they just manage to avoid being hit by a truck. They get to safety... and the clock chimes three o'clock. Don insists they go back to the diner.
Once their, they find two women at their previous table and Pat suggests they try another napkin holder, but Don insists that "their" machine has all the answers. An increasingly frightened Pat insists that the whole thing is simply a series of coincidences but the superstitious Don isn't convinced. Finally the women leave and Don starts feeding more pennies to the mystic seer. The machine says that their car will be done earlier then planned... just as the mechanic comes in and says he managed to find the necessary part early. Don has a nervous Pat ask the machine questions and despite her efforts to trick it, it seemingly answers every one of her questions correctly. She backs away from the machine and Don wonders why she's scared if she doesn't believe the machine has powers. She responds by saying that she's afraid for Don, that he's giving up his life to the machine's control. Don snaps out of his obsession and admits that she's right, apologizing. Taking command of his own life, he turns to the machine and tells it that he's taking back his life and that he'll go where he wants, when he wants.
Don and Pat leave. As soon as they're gone, another couple come in and sit at the table. They nervously start asking it questions and it becomes clear that the machine has them trapped.