The PLOT to me, starting from when she found out her husband was still alive onward I understood very little fully....especially (but not only) i) Why did Goldie's husband absolutely HAVE to fake his own death? and ii) WHO was really after the necklace? Just him, or others too...i don't know why for this movie specifically, but i was thoroughly confused in a lot of places...help !
He faked his death to end his life with Adrienne who was starting to ask too many questions. He figured she would let all of her suspicions die with him, but he wasn't counting on the trail of clues that would result from the SSN because it had worked without anyone being alarmed for I think 16 years.
Jack pretended to be blackmailed for the necklace by Daniel Sherman, the identity he maintained with his other wife who was unaware of Adrienne. Jack was the only one looking for the necklace that he thought was in the suitcase he carried out with him before faking his death. Unbeknownst to him, the necklace fell out of the suitcase and slipped out of view when Adrienne was searching through it and was startled by the housekeeper.
efrizellstar is correct. This was on TV last night and it made a lot more sense on a repeated viewing. I think it's one of those movies you need to watch twice to absorb all the details.