Shopping For Death

I was watching 'Alfred Hitchcock Presents' over the weekend (Friday, Fox Crime, 9:30pm-10:30pm). I missed the beginning of the first short story but the twist in the end was a good one. The second short story was titled 'Shopping For Death'. I confess that I didn't understand this one much. What impressed me most, however, was the acting by one of the 3 main characters - a lady who is so harassed by her poverty, miserable existence and soaring heat that she practically bites the head off anyone who dares to cross her path. As I watched her, I simply forgot that she is an actress who is essaying her part. She seemed so natural. I have no idea what her name was but she did one helluva job!