John Sappo is an everyman whose misadventures in everyday life (such as trying to catch the 5:15 train) dominated the series at first, however, after he took in a tenant known as Professor O. G. Wotasnozzle, his antics began to involve the Professor's daring inventions and experiments. Although usually annoyed by the Professor's schemes, Sappo would at times find himself going along, tempted by the prospect of riches and success, only to end up facing catastrophe.