Traveling dentist O'Connell traverses South America on his motorcycle for the 'Eversmile' foundation of New Jersey, in a fight not only against cavities, but also against fear, ignorance, indifference - and established antediluvian dentists. During a stop at a lonesome garage he meets Estella, who is supposed to marry a few days later. However she'd rather come with him - to meet a former boyfriend in another town, she says. Expecting problems, he refuses to take her, but she tricks him into it and then tries hard to convince him of her qualities and let her stay with him.

Frost is arrested and committed for murder after he is apprehended burying his victims in the garden. However, even while under psychiatric care and tight hospital security, it becomes obvious that Mr. Frost is not all he seems to be.