Gary Nelson, who made this, also directed The Black Hole and Freaky Friday, which is an interesting set of films to have on your IMDB. He also made this TV noir, which is all about a man trying to find a woman who has faded away.
The cast makes this, including Don Muray (Bus Stop), Van Johnson, Bery Convy (before his game show days, Convy would show up in movies like Jennifer), Joe Santos from The Rockford Files, Yvonna De Carlo, John Ireland, Walter Pidgeon, Cameron Mitchell (!) and Candice Rialson (!!)
The closer the investigation gets to the answers, the more people die. Much like a lot of mae for TV movies, this was a backdoor pilot for a series, which I really wish had happened. This combines so many noir movies into one film, like Laura for one, with a fair bit of Sunset Boulevard.
Gloria Grahame plays the woman who everyone is looking for, who we also see in the film in two clips of her most famous noir appearances, Human Desire and In a Lonely Place. I wonder where else future installments of this series would go.
This was hard to find for a while, but thanks to the internet, we can find it on YouTube.