The Caretaker

 

 (wikipedia)

THE CARETAKER-1963-Harold Pinter's play adapted for the screen by the playwright himself and directed by Clive Donner. The three cast production has a soft spoken lonely man Aston (Robert Shaw) with a history of mental illness helping a grubby manipulative old man Jenkins (Donald Pleasence)) by letting him stay in his cuddled run down room at their family house. Also there is Aston's brother Mick (Alan Bates) who torments Jenkins. You might not go for the story that much but the acting is fantastic! Pinter has a brief cameo (the only other role). 

Along with Pinter and Donner, the stars also helped produce it (and received no pay). However, when additional funding couldn't be obtained a group of investors (including Richard Burton and Peter Sellers) was organized. Shaw and Pleasence had both been in the original stage production.

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