Magnum, P.I. (1980)

Having once been hired by wealthy, blind Agatha Kimball to find her missing grand-daughter Amy, Magnum's services are once again called upon by his elderly friend after she has been contacted by a black-mailer claiming to have some important information about Amy. She instructs Magnum to pay the man and get rid of whatever the information about Amy is without investigating further, but when Agatha is nearly killed in a series of suspicious accidents, and when the black-mailer is shot dead during the delivery of the ransom, Thomas decides he must ignore instructions and investigate just what trouble his elderly friend and her grand-daughter are in...