The Night of the Iguana (1964)
A defrocked Episcopal clergyman leads a bus-load of middle-aged Baptist women on a tour of the Mexican coast and comes to terms with the failure haunting his life. This is how the IMDB describes the film. It isn't quite clear whether the clergyman (Burton) is truly "defrocked" or just pushed out of his parish...not that it matters much for the character.
Burton is down on his luck, that much is certain, and he finds himself as a mere tourist guide for sites inside Mexico -- to no pleasure of Judith Fellowes (Grayson Hall) who can easily see through Burton's flim-flam artistry. Additionally, she can see that one of her young passengers, Sue Lyon, is attracted to Burton. Burton doesn't encourage any kind of relationship, but Lyon has her own view of things -- not to the advantage of Burton.
In a kind of desperation, Burton leads the bus to a known friend/accomplice (Ava Gardner) who basically rescues him from certain condemnation.
It is here that we come upon Deborah Kerr and her ailing grandfather. Through Kerr we come to realize the extent of Burton's alcohol addiction (physical and psychological) -- something of which she knows about first hand -- as well as the quiet night to which her elderly and fragile grandfather (a poet) must eventually succumb.
For Tennessee Williams' fans, this is a real treat.