The nearly four hour documentary Leaving Neverland has become the talk of the 2019 Sundance Film Festival.

The two-part film from director Dan Reed premiered to long lines for its festival showing Friday, featuring detailed interviews with Wade Robson and James Safechuck, two men who allege they were the victims of sexual abuse at the hands of the late pop superstar Michael Jackson for many years, starting when they were boys.

Tweets from attendees indicate that the subject matter is jaw dropping:

The two men, who ardently defended Jackson in 1993 when he was accused by other young men of child molestation, themselves came forward with sex abuse claims in 2013 and 2014, after coming to grips with what they said they had experienced as boys, and after each tried unsuccessfully to sue Jackson’s companies. Vanity Fair reports their cases were eventually thrown out by the courts due to an expiration of the statute of limitations.  Jackson died in 2009 at the age of 50 of an overdose of the medical anesthetic propofol, which he had been improperly using as a sleep aid.

Among the young men’s stomach churning allegations in the film – that Jackson convinced them, starting with Robson at age 7 and Safechuck at age 10, to bend over and spread their butt cheeks and suck on his nipples as he masturbated, and give and receive oral sex with him. They say Jackson had installed an elaborate alarm system to prevent anyone from catching him having sex with the young boys. The film also includes details about their mothers who on the property during these vile get togethers, incredulously oblivious to or in denial about what was happening behind closed doors. The film includes audio recordings of the phone calls and letters that Jackson sent to the boys. Each of the young men, who say they were not compensated for participating in the film, says Jackson ended his relationship with them once they reached puberty.

Not surprisingly, Jackson’s most diehard fans have been sharply critical of the documentary ever since it was announced, upset that it is besmirching the legacy of a dead icon. And Jackson’s estate has denounced the film as “yet another lurid production in an outrageous and pathetic attempt to exploit and cash in on Michael Jackson.”

Leaving Neverland is slated to air on HBO and Britain’s Channel 4 as a two-night event this spring.