What starts as a pleasant summer on Cape Cod for Doc and Mary Adams turns suddenly chilling. When a house guest is murdered in his bed, with the very pills that control his epilepsy, their son Jack is the prime suspect. After all, Andy had been Jack's rival both at Woods Hole Oceanographic Institute and for the attention of a beautiful whale watcher named Alice.
The evidence is too damning to ignore, but an enraged Doc knows his son is innocent. He sets out to prove it, and his only clue is that the real murderer must have been very interested in the victim's top-secret lab work.