Monster is a 2005 horror novel written by Christian author Frank E. Peretti. The novel deals with Christian views on random mutations, natural selection and the theory of evolution. The book's treatment of evolution is through the terrible consequences of a scientist's experiments on chimpanzees in an attempt to prove that apes could evolve into humans.
The novel begins with a couple, Reed and Beck Shelton, who, along with some friends, are camping in the Idaho wilderness. Reed is very excited about the trip, but Beck would much rather stay home in the comforts of daily life. Reed is trying to get her to broaden her horizons by taking her into the wilderness for a week.
As the couple approach the cabin that they are going to be staying at, they find it trashed and partially destroyed. Reed suspects a bear, so he and Beck stay up on a knoll overlooking the cabin for the night. However, that night the two are awakened by the sound of something rummaging through the cabin's remains, followed by a series of eerie howls. Finally, in a panic, the two run back down the trail they came on but Beck falls over a waterfall and is knocked unconscious at the bottom. Reed sees a giant creature carry her off into the night. He tries searching for her, but eventually gives up and falls asleep in a meadow.
Meanwhile, their two friends, Michael "Cap" Capella and his wife Sing are on their way to the campsite, unaware of the carnage that has taken place. They stop at Abney, a small alpine village on the edge of the Idaho wilderness, where they spend the night at a small hotel. The owner, Arlen Peak, tells them of some strange occurrences that have been taking place. Herds of elk have been running through the area when it isn't migrating season, and some high-pitches howls have been heard in the woods at night. Arlen believes that it is a bigfoot.
The next morning, Cap and Sing find Reed in the meadow. He tells them about the awful events that had taken place the night before, and they take him back to the hotel with them. Soon afterwards, a search party is organized the try to find Beck.
Beck wakes up to find herself in the arms of a gigantic gorilla-like animal, which seems to be trying to feed her serviceberries. Beck refuses at first (because she can't swallow the amount that is being forced into her mouth), but concedes shortly after realizing that it may be all she will eat for a while. The animal is alerted to the sounds of hunters coming through the woods, and runs off with Beck in its arms. They eventually end up with several other of the creatures, who turn out to be actual sasquatches. At first Beck only sees her abductor's rival and her single offspring, but then later meets the alpha male, who is none too pleased to see her. Nonetheless, she is accepted as one of the group. She even comes up with names for them: the big red one, her abductor, is named Rachel (after the biblical Rachel who was Laben's daughter), Leah (after Laben's other daughter), her son Rueben (after Leah's firstborn son), and Jacob (after Isaac's son and the husband of the two), the alpha male.
Reed tries to convince the party that it was no bear that did the damage, but most of them refuse to believe and proceed to set out bear stands in an attempt to capture one. Arlen seems to be the only one who will believe Reed, as no bear would have simply picked up a person and carried it. Cap, on the other hand, wishes to find out for himself what it was, and soon has his opportunity as another attack is reported not far away, by a young couple by the name of Ted and Melanie Brooks. Cap takes the saliva and dung samples left by the beast and attempts to get them analyzed at the university that he used to work at as a professor, before being fired because he was repeatedly finding problems with Darwinism. The samples do not match any known creature, as they seem to contain the DNA of a chimpanzee, that has been contaminated with human DNA. Soon he meets up with several of his former co-workers, who seem to be trying to cover something up. This becomes apparent when Cap begins investigating the office of his former co-worker, Adam Burkhardt. He finds several jars, with preserved specimens of various mutated animals, none of which have survived.
Beck gradually adapts to the ways of her new "family", but it soon becomes apparent that the sasquatches are running from something. Beck thinks it may simply be hunters, and she soon discovers that several of them are indeed out, looking for her. They are anything but successful, however, as the sasquatches are extremely adept at hiding and blending in with their surroundings. However, one man, by putting out fruit as bait, manages to capture some footprints.
Cap soon discovers that Burkhardt has moved out, and manages to convince his friend, Nick, to tell him where his former colleague went. It turns out that the professor has moved his lab to the wilderness, so that he can study and experiment alone, "without probing eyes". As Cap tours the lab, he finds several of Adam's accomplishments, which are either dead or deformed chimpanzee embryos. Finally, entering the back room, he finds several monstrous creatures that have been created. One of them has escaped from its cage and into the wilderness, and now Cap knows what has been doing all the killing. As he prepares to exit the lab, he is caught by one of the professors at the university, Phillip Merril, and two campus policemen. Cap, using the hideous, deformed creatures in Burkhardt's lab, demonstrates how mutations cannot work to produce a higher form of life, even controlled, purposeful mutations. Finally, he manages to get out and goes back to get the police.
Reed is further convinced that the creature that has been doing the killings was not a bear, when it kills his boss, Sheriff Mills, by wringing his neck, the same way as it had killed all the others. The others continue to search, but when Reed finds a piece of his wife's bloodied buckskin jacket, he is convinced that she is dead and gives up. However, upon investigation he finds that it is several days old, and continues. Soon, a conspiracy is apparent, as Sing is nearly killed by a member of the team, and the head of the search party, Pete, is murdered by another. Reed is nearly killed, but manages to kill his foe before he can try again.
The sasquatches are running again, this time from something that is definitely not human. Rachel suddenly decides to take a small side-trip, apparently smelling something familiar. In the brush, Beck sees the mostly-eaten corpse of a sasquatch child, with some reddish-brown hairs still on it. Beck realizes that Rachel must have lost her child to the brutal killer that fateful night when Beck and Reed were camped on the knoll, and that Rachel mistook Beck for her own child. As she howls mournfully, she is hurried off by Jacob, leaving Beck alone in the woods. Making her way down the mountain slope, Beck hears something behind her. She turns and soon sees a creature coming through the trees; a hideous, deformed chimpanzee-like beast. It tries to kill her, but then it is killed by a shotgun. A hunter steps into the clearing, and introduces himself to Beck as Adam Burkhardt. He tells her that the monster is the result of "an experiment gone horribly awry", and that it has been doing the killings. Finally, he reveals that he is here to kill her, so that no one will find out about his experiments. However, just as he is about to, Jacob appears in the clearing and knocks him away.
Reed soon finds Beck in the clearing, and after managing to convince Rachel that he is not a threat, she reunites with him. However, soon they are confronted by Adam Burkhardt, who Reed identifies as Max Johnson, a member of the search party. Burkhardt had been in the party all along, under an alias. He tells them that he "must survive" and kill them, but Reed finally puts some sense into his head by telling him that he will end up like his monster if he does so. Adam surrenders and is placed under arrest as Cap arrives with the police.
Through Monster, Frank Peretti shows the flaws of evolutionary thinking, through the ever-popular science fiction genre. Adam Burkhardt had tried to prove that evolution was true by producing a stronger, more dominant creature through viral transfers. However, he proved nothing other than the exact opposite: mutations cannot produce a higher form of life, and all they are able to do is cause deformities, disabilities and death. Burkhardt had intended the animal to be dominant, but had instead produced a deranged killer.