Astrid discovers she is able to sense the thoughts and feelings of unicorns and she travels to France to work with a scientist to figure out how the mysterious remedy to unicorn venom works. Astrid is a unicorn hunter whose job is to slay dangerous, man-eating unicorns that wander into human cities and towns. In the first book of this Killer Unicorns series (Rampant), Astrid finds out she is a unicorn hunter and travels to Rome to join the Cloisters of Ctesia, a place where young unicorn hunters train.
This second book of this series begins with Astrid going hunting with the other girls in the Cloisters, killing unicorns and harvesting their alicorns (the unicorn horns). After a long day of hunting they return to train in the Cloisters. Unicorn hunters can become more agile and strong when a unicorn appears in their vicinity or when a piece of the unicorn's horn is nearby. Because it contains so much unicorn-related material, the Cloisters is like a giant tuning fork that absorbs the energy from nearby unicorns to help the hunters remain in their enhanced state so that they can train. One of Astrid's friends, Cory, thinks something is wrong with her because her sense of unicorns has been lower and her agility has not been the same, lately.
Cory tries to “re-tune” her hunting powers by touching the ancient alicorn throne in the Cloisters but nothing happens and she becomes very depressed. She vows she will kill all the unicorns one day but Astrid thinks mass extinction is not the solution to the unicorn problem. Meanwhile Astrid checks in with her cousin Phil, who is ironically running a campaign to protect unicorns from being hunted to extinction while she is also helping to run the Cloisters.
Astrid goes on a date with her boyfriend Giovanni. She has a complicated relationship with Giovanni because, as a unicorn hunter, she must remain celibate or else lose all her powers. Giovanni knows this but still loves her. On their date, he tells her that he will be going back home to New York to attend an art school. Astrid is sad and thinks that their long distance relationship may not work, even though Giovanni insists there is no one else for him. He insists they try to make it work.
One day, the Cloisters get a visit from a member of the Vatican who has decided to support them financially. In return, however, he insists on making new rules which the girls will have to follow. The girls are all grouchy about being told what to do, considering they have been on their own for a while, now. The new policies include a required uniform both for hunting and for visiting Rome as well as the strict rule of no interaction with boys.
Over the next few days, Cory continues to complain about losing her hunting powers. The Cloister's resident pet unicorn has been reacting weirdly when she's around and on one of their hunting trips, the unicorns are unusually aggressive to Cory and she can't sense them approaching. The head of the Cloisters wants to send Cory home because it's becoming too dangerous for her to continue hunting unicorns, now that her powers are weak.
Meanwhile, Astrid's mother is becoming more involved with the media. Astrid, in particular, is the "rock star" of unicorn hunters because she's a descendant of Clothilde Llewelyn, who was the famous unicorn hunter that killed the rare and monstrous karkadann unicorn many centuries ago.
One day, Neil asks Astrid to accompany Cory to the U.K., where she will recuperate from her injuries and be far away from unicorn attacks. At first Astrid is grumpy that she is being sent as a glorified bodyguard but Neil reveals that he also wants her to track down a man named Seth, who was involved in a pharmaceutical company (Gordion Pharmaceuticals) that, in the first book of this dulogy, was wrongfully doing experimentation on unicorns. Astrid agrees to take on this mission.
On the way to London, Astrid makes a detour to France where Seth is supposedly hiding. To her surprise, she runs into an old ex-boyfriend, Brad, who now calls himself Brandt. Brandt was Astrid's first boyfriend and in the first book of the duology, he was attacked by a unicorn. Astrid's mother healed him with an ancient elixir called the Remedy, whose composition is unknown. Last Astrid heard, Brandt had run away. Brandt tells her that he now works for Gordion Pharmaceuticals as a sort of human test subject. The pharmaceutical company has been trying to figure out how the Remedy works as an antidote to the venom in the unicorn horn.
Brandt takes Astrid to Gordion Pharmaceuticals where Astrid talks to the head of the company. She learns that Seth's whereabouts have been unknown since new leadership has taken over. Brandt shows Astrid a herd of einhorn unicorns that are kept under control with electrical collars. While taunting one of the einhorns, Brandt is stabbed by a unicorn horn. To Astrid's surprise, his wound stitches up immediately. Before she leaves, the new head of Gordion Pharmaceuticals, Isabeau, offers to pay for Astrid to work as a resident unicorn hunter on their premises and keep the einhorn unicorns in line. She even tempts Astrid with free tuition to attend the nearby Limoges University, where Astrid can learn about medicine, which has been a passion of hers. Astrid decides to accept the job.
Isabeau tells Astrid about how she is also a Llewelyn descendant, but she has taken up interest in the science behind natural, herbal remedies. Isabeau keeps two pet einhorn unicorns that Astrid feels are different from other unicorns because she can't sense their thoughts. Isabeau explains that the unicorns are receptive to the thoughts of the hunters and if Astrid continues thinking with hostility towards the unicorns, they will continue to attack her. Astrid tries this on the resident einhorn and finds that it works, as they approach her without attacking her. As the months pass, she becomes friends with the unicorns. She notices that many of them seem to be suffering from illnesses of some sort. One day, Isabeau asks Astrid to euthanize one of the unicorns so that they can do more research on the Remedy. Astrid is devastated but she understands her duty. That night, she injects the poison into one of the unicorns, but it doesn't die peacefully. Astrid realizes that the unicorn's own body is purifying the poison. In the end, Astrid has to slit its throat.
One day, the electric fence around the unicorn enclosure is momentarily down and the einhorn unicorns try to escape. Astrid rushes to help manage the einhorns while the repair crew fix everything. One of the unicorns gets injured and she realizes that she can feel what the unicorns are feeling. After healing the injured unicorn, the other unicorns seem to defer to her as some sort of savior.
As the months pass, Brandt starts to flirt with Astrid and Astrid can't help but be charmed, even though she's supposed to be with Giovanni. One day things almost go too far, but Isabeau stops Brandt in time. Astrid realizes that her new job is no better than the Cloisters since her life is still being watched 24/7 and she's not allowed to be free. She decides to return to Rome and rejoin the Cloisters.
One day while she and the other hunters are out on a mission, Astrid is attacked by a unicorn. She wakes up months later only to be told that she was in a coma and when she had woken up, she wasn't herself for months. She's told she had a brain injury which has incapacitated her and she may never be able to connect with unicorns again.
Dejected, Astrid visits Isabeau and learns that the woman has already reproduced the Remedy. She gives Astrid the Remedy in the hopes that Astrid will be able to regain full brain function. Astrid is very grateful but later that day, Brandt reveals that there are side effects to using the Remedy. Apparently, ever since he began using it, he's been able to sense unicorn hunters. He explains that the Remedy makes him intoxicated by Astrid's presence. Brandt tells her that the secret of the Remedy isn't to do with the unicorns but rather to do with the unicorn hunters. She learns that they've actually been doing experimentation on her not the unicorns.
Enraged at being betrayed yet again by people she'd learned to trust, Astrid frees the resident einhorns from Gordion Pharmaceuticals. She destroys Isabeau's research notes –but not before she finds out that Isabeau had used her half-sister as a unicorn hunter. She never knew she had a half-sister because her father mysteriously disappeared when she was young. She travels to Germany to find this half-sister, named Marikka. The story ends with Astrid meeting Marikka for the first time and learning that, as a unicorn hunter, she'd rather use her unicorn hunting powers to learn more about the unicorns than vanquish them.
Best part of story, including ending:
I like that this story is about Astrid trying to find peace with the unicorns. The first book of the series, Rampant, was quite blood-thirsty and all about slaying the unicorns because they were always foaming and half-mad when the hunters encountered them. I like that in this book, the docile and gentle side of the unicorn is revealed and Astrid is able to bond with them.
Best scene in story:
My favorite scene was when Astrid frees the einhorn unicorns that were caught by Gordion Pharmaceuticals. It was a nice release for Astrid, who had been struggling to come to terms with the fact that she's a unicorn hunter that doesn't want to hunt unicorns. The act of freeing the unicorns meant she had decided that she was going to leave the unicorn hunting business for good.
Opinion about the main character:
I didn't like that Astrid was cheating on Giovanni with Brandt. But, to be fair, she did tell Giovanni that their long distance relationship wouldn't work. I like that Astrid was able to think outside of her role as a hunter and see the bigger picture of human-unicorn interactions. Because she was so open-minded, she was able to connect with the unicorn and show them compassion.