Name That Trauma:: Reader X on a Dead Soldier's Kept Promise

You were recommended to me by Sound on Sight.

First, there's no kids in this movie I'm looking for.

I believe it was the movie of the week on ABC during the mid-70s.

It's about this woman who's about to be remarried. Her first husband died in Vietnam. She starts getting phone calls apparently from her first husband. All he says is, "Remember the promise." She thinks it's the promise she made to always be faithful to him. There are a couple attempts on her life. A buddy of the dead husband has been around during this time. And the climax is at a lake and the buddy is trying to kill her. Somehow he gets in the water. When he tries to climb out, something grabs his leg. Michael? I believe that was the dead husband's name. The buddy gets dragged back into the water and drowned. After it's over, there's a flashback where the first husband is reminding the woman that he'll always protect her.

For some reason I thought the name of the movie was, "When Michael Calls." But, my research has shown that is another movie.

Any help would greatly be appreciated.