I generally liked this episode. Daphne was a wonderfully complex and evil young lady---and she was very entertaining. My only reservation is that the ending seemed only okay. Still, compared to most modern shows, this is a heck of a lot better.
It all started quite innocently a few weeks earlier when Daphne and her mom Sarah Middleton, Nina Foch, met handsome free love enthusiast and sculptor Hugo Myrich, Gig Young, at their hotel swimming pool who made a play for them looking to have a free for all romance with mother & daughter. It turns out that after bedding down Mrs, Middleton, who seems to be estranged form her husband, the hot in his pants Hugo went after the much younger and prettier Daphene as well. Everything is just fine and groovy for Hugo until Daphne learns that he's romantically involved with her mom as well as herself! That has Daphne throw a fit and have Hugo meet her at Frederick Bergen's pad on the Riviera for lunch, with Bergen doing the cooking,and talk things over. As it turns out Hugo after telling Daphne just how much he loves her, which she knows is a pile of BS, pushes him off the guard tower to his death bellow in the choppy Mediterranean Sea.
****SPOILERS**** Getting back home to tell momma the news Daphne is shocked to find out that she's in a deep state of depression in that the late Hugo left her a "Dear Sarah" letter telling her that he doesn't love her anymore and is taking off to Paris France to chill out! It doesn't take long for Sarah to do herself in, with a bottle of sleeping pills, and her daughter Daphne, who's pills momma did herself in with, to become the #1 suspect in her death! It's here were we find out what Bergen-who seems so out of place-has to do in all this. And it's in him blackmailing Daphne, who's some 30 years younger then him, to marry him or else's he'll spill the beans, not sleeping pills, in her being responsible in Hugo's murder: With an arm load of evidence to prove it!
P.S Even though with a fate worse then death facing her in marrying the messed up looking Bergen which 30 years behind bars, in being convicted in Hugo's murder, would have been a great improvement Daphne did get a lucky brake in the end. That in Bergen or Peter Lorre who played him having passed away, very probably during sex with her, six months later from a massive heart attack! That made her stay with him that he expected to last 30 to 40 years far more bearable.