Professor Roger Markle is leading an exploring expedition in a cave in Arizona when the wall of the cavern collapses. Three of the students have been found but Professor Markle has not been found and is presumed buried alive. His wife Anne Markle cannot accept that her husband is dead but realises some weeks later that she has to start restarting her life. On a trip to Mexico with her friend Madge she comes across a painting of her husband in a shop window with a date on it that was 3 months after her husbands accident. Ann is now even more convinced that her husband is still alive somewhere and she determines to find him.