Judy Garland and Marilyn Monroe, two of the biggest superstars of their day, were friends and confidantes who shared a haunting bond, according to a new book by Garland's third husband, Sid Luft.

Judy and I - the memoir Luft left unfinished before his death in 2005, and excerpted in this week's PEOPLE - reveals new details about their poignant friendship, and the shocking revelation that Monroe had once asked Garland for help before she died from an accidental drug overdose in 1962.

According to Luft, Monroe's death was "especially troubling to Judy since Marilyn had been one of Judy's telephone pals during her years of insomnia."

The book also includes an excerpt from an article written by Garland about Monroe for Ladies Home Journal in 1967, in which she revealed a haunting conversation she'd once had with the star.

In the article, Garland described a Hollywood party one evening in which Monroe followed her "from room to room."

"I don't want to get too far away from you," she said. "I'm scared!"

See more info here...