Asked to describe her state of mind as she prepares to begin her senior year at Columbine High School on Monday, Kathryn Ulibarri answered with the self assurance of someone who had given it considerable thought and come to a firm conclusion: "Nervous, but ready."

Ulibarri's terse response is a fair summation of how this community feels as it prepares to send its students, faculty and administrators back to a building where on April 20 two disturbed, alienated teenage boys killed 12 students, a teacher and then themselves in an orgy of inexplicable violence that rocked the nation.

On Monday morning, Ulibarri and her nearly 2,000 fellow students at Columbine will gather in a parking lot--the same one crossed by Eric Harris and Dylan Klebold as they began their murderous assault--and stage a "take back the school" rally. School officials will deliver speeches, cut a ribbon and raise an American flag that has remained at half-staff since the attack. Then Columbine students will stream back into the building, which has been closed since spring.

They will find a structure that has changed since Harris and Klebold fired hundreds of rounds of ammunition and detonated some of the several dozen homemade bombs they carried, but one that also still carries echoes of that awful day. All the obvious evidence of the attack has been erased during a frantic summer-long remodeling designed to erase the scars, improve security and alter the appearance enough to mute memories.

Along with the new paint and floor tile, students will notice one more glaring change: The library where the two gunmen killed 10 people before turning their guns on themselves is no more. It has been sealed off behind a false wall that is lined with blue lockers. A temporary library has been established in modular classrooms set up near the school's main entrance, and it will stay there until a final decision is made on what to do with the place where so many died.

The library and its disappearance is an apt symbol of this community's struggle to deal with the tragedy of April 20. How to move on, while still honoring the dead and trying to understand what happened and why? How to accommodate the broader public's fascination with this place and the Columbine community's need for a respite from all the attention?

Parents of the slain students asked on Thursday that the community decide never to reopen the library because the memories of what happened there are too painful. But that view is hardly unanimous. Melissa Mendo, a sophomore who came to school this week to pick up her class schedule, was disappointed to find the library shielded. "Our friends died there," Mendo said. "We feel like we'd be there with them."

Though nearly four months have passed, Columbine students and staff members continue to live an often unwelcome fishbowl existence. Even as students swarmed into school this week to get their schedules, for example, they had to compete for parking spaces with the tourists who constantly arrive, stop to snap a few pictures and depart.

At a meeting with the media in preparation for Monday's reopening, school officials brought in a child psychiatrist to press their view that the return to Columbine should be a time to focus on the positive and not to relive the events of April 20. "The recovery of the school, the recovery of the students, staff and community depends on moving from destructive images to more constructive images," said Donald Bechtold of the University of Colorado School of Medicine.

As they have tried to shape media coverage, school officials also have been wrestling with new security plans and trying to devise strategies for early intervention with troubled youths, including ways to prevent the kind of bullying of outcasts that some believe helped drive Klebold and Harris over the brink.

The Jefferson County School Board this week gave tentative approval to major security improvements proposed by a school safety panel, some of which are already in place at Columbine. Among the changes: Students and staff will have to wear visible ID badges; more police officers will be assigned to high schools and middle schools; video cameras will be installed; visitor access will be better controlled; and panic alarms and hotlines will be put in place.

Though school officials have rejected suggestions that Columbine tolerated abusive behavior by athletes, this week the school district brought in an outside consultant who met with high school coaches and urged them to enlist athletes in efforts to increase tolerance. And Columbine Principal Frank DeAngelis is expected to remind his students of the need for tolerance at the "take back the school" rally on Monday.

But, overall, the emphasis is going to be on normalcy. To shield Columbine students from intrusive media and the curious, parents will form a human chain along the route returning students will use to approach the rally site on Monday. Outsiders will be kept at a distance. Clement Park, the sprawling county recreational facility adjacent to the school, will be closed for the day.

But almost every day here, the story goes on, and normalcy proves elusive.

The progress of the most seriously wounded is recounted in detail in the newspapers and on the nightly television news--on Thursday, Anne Marie Hochhalter finally came home, leaving only one wounded student, Richard Castaldo, still in the hospital. Law enforcement authorities announced that the parents of Harris have at long last decided to talk to them. The full report on the criminal investigation is expected in the fall. And the students and the community continue a running debate on what is being done to make the school safe and to prevent a recurrence, with occasional high-profile disagreements such as the one involving Linda Mauser. The mother of a dead student, she stormed out of one school safety committee meeting because she thought the issue was not being taken seriously.

To some students, such as Columbine senior Jennifer A. Davis, the extraordinary efforts to make them feel secure on their return--for instance, the creation of "safe rooms" with counselors for those with anxieties--is all a bit much. "I'm ready to get it over," she said earlier this week after registering for classes. "It's time to put it behind us."

But others are grateful for some of the attention to detail. Ulibarri, for example, has struggled all summer to come to terms with the shooting and the loss of four close friends. She has met with a counselor and drawn closer to her family. She has overcome her initial feeling that she would never return to Columbine. She has had to deal with blaring security alarms at her job in a suburban mall that remind her of April 20, and she is grateful the school district has changed the sound of the alarms at Columbine.

"For the first few weeks, I wanted answers," she said, recalling the feelings she had in the spring. "But there aren't any, and I know that now."