``The school's in panic, and I'm in the library,'' a teacher called Peggy is heard saying on a tape released by police. She is talking to a police dispatcher, begging for help. Peggy, who survived, says desperately: ``I've got students down . . . Under the table, kids! . . . Kids, under the table.

Kids, stay on the floor . . . Oh, God. Oh, God kids, just stay down.''Harris and Klebold killed a teacher and 12 fellow students, 10 of them in the library from which Peggy, who survived, placed her call, before turning their guns on themselves. 15-year-old Bae Gottini said it was not ``random shooting''. Gottini was cowering under a table with her friend Cassie Bernall when Harris, blood all over with ``a dumb giggle'' -- took Bernall by the hair and pulled it, handgun to her head.

Harris knew she was religious.``Where's your God now?'' he jibed. ``Please don't kill me,'' pleaded Cassie. ``I must be your God, because I'm in total control,'' he replied. ``You are not my God,'' said she. ``Tell me I am your God,'' he said. ``You are not my God.'' And with that he blew her brains out.

Another girl, Rachel Scott, was hiding behind the table but looked over the edge to see a bloodied, giggling face staring at her. ``Peek-a-boo!'' he laughed. Then shot her.

For the slaying of Isaiah Shoels, Harris lived another of his gory fantasies. Tthis time, Hitler, whom he admired and whose 110th birthday it would have been on April 20.

Despite heart problems as a child, Isiah was a remarkable athlete -- a prime target. And he was one of the few black kids at Columbine, which had led to trouble with Harris and Klebold's gang, the Trenchcoat Mafia.

Craig Scott recalls Isaiah being pinned down and jeered at. Then, one pointed at Isaiah's slightly jutting forehead, saying: ``Look at this black kid's brain! Awesome, man!'' Afterfive minutes came the bullet.

Eric Harris grew up in rural New York state, at Plattsburgh Air Force base. His father was a decorated Air Force major and young Harris a typical all-American kid. Major Harris retired to a $200,000 home in a quiet tree-lined street in Littleton. After a year, Harris befriended Klebold, from a more affluent background. Klebold's father is an eminent geologist living in a $400,000 house at Deer Creek Park in the Rocky foothills.

Suddenly, both boys gave up sports for computers. Then a student called Joe Stair, who graduated last year, turned the clique into the Trenchcoat Mafia, which Harris joined 20 months ago. Stair says he is appalled at what happened. ``We did stuff just for fun,'' he says. Not Harris and Klebold.

Chris Reilly was in a video production class, and remembers the duo's efforts: a dry run for Tuesday's carnage. It showed them, he recalls, stalking the school corridors with guns, shooting ``Jocks''. By last year, Harris had quarrelled with friend BrooksBrown and thrown a chunk of ice at his car. Brown complained to Harris's parents, after which Harris threatened to kill him. Later, Harris posted a message on his website urging that Brown be hunted down and killed. Brown's parents went to the police, three times, but they were ignored.

The Trenchcoat Mafia was, meanwhile, learning how to make pipe-bombs, and posting the recipe on the net. Investigators believe the pair had help in preparing for their attack, comprehensively armed as they were.At Columbine, students get to telecast a ``message of the day'', and on the morning of April 20 it read: ``Bet You Wish You Weren't Here. 4-20. 4-20. 4-20.'' Brown went outside for a cigarette and saw Harris getting a bag out of the trunk of Klebold's BMW. Harris, he says, called over: ``Hey man, Brooks, I like you. Get out of here. Go home.'' ``I went to have my cigarette,'' recalls Brown, ``and heard the gunshots . . . He saved my life, basically.''

By coincidence, the philosophy professor who wrote the seminalstudy on the satanist American underground -- called Painted Black -- teaches at Denver University. Professor Carl Raschke is a critic of what he calls the ``psycho-therapeutic la-la land tolerance'' of ``what is ... a phenomenon of neo-Nazi terrorism with as much of a religious basis as Islamic terrorism or Christian fundamentalists blowing up an abortion clinic.'' ``What happened,'' he says, ``was as planned and coherently motivated as an attack on a bus in Israel.''

``The problem with American democracy,'' Raschke concludes, ``is that we just don't like setting limits to unacceptable behaviour -- even when it's playing with political and spiritual nitro-glycerine.''