Monstrosity — Paul Lonardo

This novel is set on the campus of an old New England university. It's Fall and getting dreary. Jack McRae, the story's protagonist, is a local but an outcast in this college town because he felt obligated to drop out of high school and work to support his family after his father left home. While he had been deprived of realizing his dream of becoming a journalist, his sacrifice enabled both his siblings to attend local Bister University. His girlfriend, Katie, is enrolled there as well. However, their relationship, already strained by her recent diagnosis of Leukemia, is set back further when her interest turns toward a new transfer student, Martin Higgs.
When Jack begins to play investigative reporter to find out more about this student, he learns of Higgs' claim to be the lone contact to an alien intelligence that has promised to deliver a serum that will prevent anyone who is a member of his Second Chance cult from aging or dying.
Katie is quickly drawn into the cult and withdraws further from Jack, who takes it upon himself to collect the evidence he needs to keep her safe and put a halt to the cult's influence over the university and surrounding town. In order to effectively do this, he must infiltrate the inner sanctum of one of the nation's oldest educational institutions.
But he is met with much resistance, and suffers numerous setbacks, including temporary confinement in a mental institution after the death of his mother. But Jack continues to doggedly pursue the truth behind the cult, and he soon discovers that Higgs might not be delivering exactly what was promised when he observes cult members undergoing inhuman physical transformations, discovers grotesque insect/rodent creatures living inside the walls of campus buildings and uncovers the possible plotting of a mass suicide ritual.
Then Jack himself is attacked by a pair of supposed aliens, whose rubber masks are removed in an ensuing struggle, revealing two very human strangers underneath. He is now led to believe that an alien intelligence may not actually exist at all, and that the whole thing was an elaborate hoax.
But to cover up what?
An old priest, who believes that evil forces are at work, approaches Jack. The clergyman reveals that he has joined the cult so that he could learn more about the enemy and offers himself to Jack as proof to his claim.
He witnesses the priest going through a violent “molting” process, like a snake wiggling out of its old skin. However, as the priest's old flesh peels away, there is nothing left inside the discarded husk. And the priest is gone.
Just as Jack is closing in on the truth behind the mystery, Katie succumbs to her illness and Martin ultimately reveals a tangled plot centered around a secret government research project involving, not alien intelligence, but physical science and immortality on a human subatomic level.
Jack, however, is not so easily convinced by this neat explanation. Even when he is taken inside a giant particle accelerator far below ground under Bister University, he is sure that the scientific explanation had been staged to cover up actual alien visitations and human experimentation in which the government is deeply involved. The hundreds of dead bodies of the cult members inside the accelerator are only further proof for him that those behind the project will do whatever it takes to ensure that their secret remains safe.
In the aftermath, Jack is left to ponder the reality of the events. Nothing can be discounted as he is forced to consider between the options of alien conspiracy, secret government experiments or the influence of supernatural evil.