The same source.
Marilyn said she would like to go too, and although Pat had serious misgivings, knowing Marilyn's fragile state, the three arrived together by private plane.
Joe Langford, a Sinatra security employee at Cal-Neva, recalled: 'When Frank saw Marilyn, he was pretty shocked at how depressed she was.
'As soon as he got her settled in, he got on the phone with her psychiatrist [presumably Dr Greenson] and started in on the guy. "What the hell kind of treatment are you giving her? She's a mess. Why isn't she in a sanitarium?"
'He couldn't believe how broken down she was.'
Marilyn's 'vitamin shots' alarmed them all. Langford confirmed: 'She opened her purse and pulled out those syringes. I was standing right there with Mr Sinatra and Pat Lawford.
Marilyn was very casual about it. She was looking for something else and just pulled them out and put them on the table.
'Sinatra went white, like a sheet. He said "Marilyn. Jesus Christ. What are they for?" She said "Oh, those are for my vitamin shots."
'Pat looked like she was going to faint. "Oh my God, Marilyn," she said. Then Marilyn said "It's all right Pat. I know what I'm doing."
'Marilyn finally found what she was looking for: a pin. As we all stood there with our mouths open, she opened a bottle of pills and picked one out.
'Then - and I had never seen anything like this before - she put a small hole at the end of the capsule, and swallowed it. "Gets into your bloodstream faster that way," she said. She turned back to Pat and said "See, I told you I knew what I was doing."'
Later, Marilyn collapsed in her room and was found, just in time, by Pat.
'Frank Sinatra didn't know what to think about any of it,' said his valet, George Jacobs. 'He was upset, though. He loved Marilyn, yes. But for her to maybe die at Cal-Neva while he was there? That would have been terrible.
'So he said: "Get her out of here and get her out of here now." And that was it. We had to do what he said. I mean, the woman was sick. But as compassionate as Sinatra was, he had a line and she crossed it.'
Stacy Baron, another guest staying at the lodge, recalled: 'I was in the lobby and I saw Peter Lawford on one side of her and Pat on the other side and they were practically carrying this woman out. I got a real shock. It was Marilyn Monroe.'
On Marilyn's last day alive, August 4, 1962, Dr Greenson left her home in Brentwood at about 7pm, requesting that Eunice Murray, the housekeeper he'd employed for her, spend the night there to keep an eye on his patient. Around that time, Peter Lawson called to invite Marilyn to a dinner party at his home, but she declined.
Marilyn brought a telephone into her bedroom and closed the door. It appears the rest of this last evening would be spent alone in this room.
It seems that she continued making telephone calls. Later that night, Peter Lawford called again. This time, he could sense Marilyn wasn't well. According to Peter she said: 'Say goodbye to Pat. Say goodbye to the President, and say goodbye to yourself because you're such a nice guy.'
This would seem to indicate that she was thinking about taking her life. Alarmed, Peter called Marilyn again; the line was engaged. He mentioned to his business partner, Milton Ebbins, that he was worried and wanted to go to the house, but Ebbins was afraid that Marilyn had overdosed and didn't want Peter - the President's brotherinlaw - to be the one to find her.
Ebbins called Marilyn's attorney, Mickey Rudin, who then rang the house at 9pm. He spoke to Eunice Murray, who told him that Marilyn was fine, but whether or not Eunice was able to confirm this (or even had an interest in doing so) is unknown.
The conflicting accounts of Marilyn's death occur after this time. The most often told version is based on official statements by Eunice Murray and Dr Greenson. At around 2am, Eunice called Dr Greenson, alarmed because Marilyn's door was locked. Greenson showed up five minutes later and went around to Marilyn's window.
He saw the actress on her bed, frozen and lifeless.
Breaking the glass, he let himself into the room. Once inside, he realised that she was dead, lying face down, holding her telephone in her right hand with open bottles of pills on her nightstand.
With the passing of the years, many murder theories developed. Some involve Marilyn being killed by Bobby Kennedy, or on the orders of Bobby to protect the Kennedy name.
Some implicate Peter Lawford, some the FBI, Dr Greenson, Eunice Murray, the Mafia.
Are there suspicious circumstances around Marilyn's death? Absolutely. For instance, the doctors and Murray waited almost two hours to contact the authorities. Why?
No one has ever sufficiently answered that question. More intriguingly, Eunice would later say that there was no lock on Marilyn's door. If that's the case, then the entire story of how she was found seems to fall apart.
There was very little drug residue found in Marilyn's stomach - and what was found wasn't properly analysed. Also, there was some discolouration in her lower intestine.
Do these facts support the theory that maybe she was given a lethal enema by someone?
Not really. Marilyn was a drug addict. It is a medical fact that an addict's stomach becomes accustomed to the drugs of choice and that they easily pass into the intestines. Many addicts die without a trace of pills in their stomachs.
Certainly, if she died today, with current science, there would be no mystery. So, the question remains: Suicide or murder?
If she had been a stable woman who had never overdosed in her lifetime, then, yes, one might legitimately question the circumstances of her death. However, this was a woman who had overdosed again and again - sometimes, it seemed, intentionally, sometimes maybe not.
She could have died on any number of those occasions were it not for those who found and revived her.
Perhaps the only real question about her death is whether it was intentional, or whether she hoped, on the night of August 4, that yet again someone would find Marilyn Monroe in time to save her from herself.