At least according to the teachings of the Heaven's Gate sect, the largest mass suicide on American soil to date was not suicide, but just a journey to the "next level."

When investigators from the San Diego County Sheriff's Office came to a property on Colina Norte in the Rancho Santa Fe suburb 25 years ago, they noticed the smell of decay.

In the house they saw a bizarre picture.

In the bedrooms 39 corpses: carefully covered, in identical black outfits, black and white sports shoes and a purple cloth over their faces.

The 21 women and 18 men wore bracelets on their wrists with the inscription "Heaven's Gate Away Team".

In the days leading up to March 26, 1997, the cult leader, former soldier and preacher Marshall Herff Applewhite,

sent a self-made video with a farewell greeting.

"We left our vehicles," said the 65-year-old Texan.

As the autopsy revealed, Applewhite and his followers took their own lives with the sleeping drug phenobarbital mixed with pudding and applesauce in order to ascend to the sky without their body ("Vehicle") as immortal extraterrestrials - on board a UFO modeled on the TV series "Starship Enterprise".

Starship Enterprise fans

Applewhite had been working towards this day for more than 20 years.

The minister's son, who tried to be "cured" of his homosexuality in a hospital in 1971, met the nurse Bonnie Lu Nettles there.

With her, in the 1970s, which was open to experimental forms of life, he developed the doctrine of “Human Individual Metamorphosis” (HIM).

The mixture of Bible studies, science fiction and millenarianism was intended to prepare Applewhite ("Do"), Nettles ("Ti") and their disciples for the opening of heaven's gates.

With a few dozen followers, the couple roamed the United States for years, sleeping in tents and surviving by begging.

The rules of Heaven's Gate were as simple as they were austere: they banned sex and drugs;

some male members, Applewhite among them, volunteered to be castrated.

The cult leader saw herself as Jesus' follower, Nettles, who died of cancer in 1985, as a bearer of the divine.

One of the first sects of the internet age, Applewhite and his disciples shared their theories with non-believers via video.

As fans of the series “Spaceship Enterprise” and films like “Close Encounters of the Third Kind” they always looked to fictional role models.

Even 25 years after the mass suicide, "Heaven's Gate" is still alive.

The "culture of conspiracy," with believers on one side and a hostile world on the other, that historian Michael Barkun sees in Applewhite's teachings seems to continue to intrigue many.

The Himmelspförtner website will also continue to operate - with the note that suicides are rejected.

The spaceship to the next level, it says, can only be reached with the "physical body".