'Kotch' (Walter Matthau) is a doting grandfather who lives with his son 'Gerald' (Charles Aidman), his wife 'Wilma' (Felicia Farr) and their young son 'Duncan' (Donald Kowalski) whose antics are frequently the cause of his troubles. Meantime, his daughter-in-law hires the young 'Erica' (Deborah Winters) to do some childminding and of course, grandpa doesn't approve. It's whilst he is doing some illicit snooping of his own, he discovers that she and her boyfriend aren't being very discreet - but how can he alert 'Gerald' without admitting he was where he never ought to have been? 'Wilma' has…