There's been a fair amount of actresses playing Agatha Christie's favourite spinster, but I find Helen Hayes does a fine job as Miss Marple, capturing that "old sweet looking old lady but with great observation skills" really well. Sure, her accent can occasionally slip into an American tang, but, for me, it's not that noticeable - nor does it distract from her rather lively performance. Like my favourite Marple, Margaret Rutherford, she's a fun Marple and not sour-faced like the other actresses who played her.
The story- Detective Miss Marple (Helen Hayes) is on vacation, luxuriating in an opulent Caribbean resort. She meets quirky mystery writer Maj. Geoffrey Palgrave (Maurice Evans), who giddily informs her that he believes one of the other guests is a wife-murdering serial killer. But before he can reveal the alleged killer's identity, Maj. Palgrave dies under suspicious circumstances. Soon there are other victims. Now, Miss Marple must take on the case before more are murdered.
A Caribbean mystery moves at a leisurely pace, and is quite entertaining- close attention is paid to the motley crew of suspects and when the murderer is unravelled you're left satisfied.