Her father, Joe Old Coyote, was a rodeo bull rider, who died a few days after consummating his relationship with her mother, Margi.
Mercy inherits a gift from her father, giving her just enough of an edge to survive amongst the werewolves, fae, and other creatures that may want to eat her during the night; she is a "Walker"—a Native American shapeshifter not linked to the moon, who turns into a coyote.
In Homecoming, a graphic novel, Mercy travels to the Tri-Cities of Washington for a job interview and quickly finds herself smack-dab in the middle of a gang war between rival packs of werewolves.
She's a walker, not only capable of shifting into coyote shape at will but also possessed of a sharp nose for scenting other creatures and an ability to sense magic when it is at work.
Before you can say "from the frying pan into the fire," things go awry and Mercy finds and just barely saves a wounded Adam, whose fifteen-year-old daughter Jesse has been kidnapped by the same people who came after Mac.
There we meet Bran, leader of all the North American werewolves, whose son Samuel is the man whom Mercy once loved and lost.
Stefan is fearful that the visiting vampire has some type of magic that can compel him to do things he would not ordinarily do and that Mercy is hopefully immune and will be able to report back to his seethe should anything happen to him.
Of course, things go badly and soon Mercy is wrapped up in a hunt for the vampiric sorcerer Cory Littleton, who is causing the Tri Cities area to have an increased rise in violence, harming werewolf friends, and endangering lives of innocents.
Both are extremely dominant werewolves, although Samuel is a lone wolf and Adam is the alpha of the Tri Cities werewolf pack.
[3] Bone Crossed begins with the arrival of Stefan, Mercy's vampire friend, on the floor of her living room, flayed, starved, and barely recognizable.
The Mistress has had a pair of crossed bones placed on Mercy's door, magicked so they can't be removed, as a sign to other vampires and minions that she is a traitor.
While Stefan is recovering, he accidentally floods Mercy's mind with his, reliving the deaths of his menagerie, and Adam brings her into the pack to snap her out of it.
Mercy discusses it with Adam, Samuel, and Bran, who tell her that there is only one powerful supernatural creature in Amber's home city of Spokane, the vampire Jim Blackwood, called The Monster.
When they get back, two rebellious vampires from the seethe (not made by the Mistress and not easily disposed of because of who their maker is) come to Stefan separately to ask him to help them remove Marsilia.
Stefan finds her, and she convinces him to save Chad, on the condition that should she survive, he will be forgiven for the deaths of the two people he had killed in Blood Bound.
When mechanic and shapeshifter Mercy Thompson attempts to return a powerful Fae book she'd previously borrowed in an act of desperation, she finds the bookstore locked up and closed down.
A weird message from Bran (The Marrok, ruler of the North American werewolves) arrives ... "The Game is Afoot" ... Adam's ex-wife, Christy Hauptman, calls in, she is in distress.
Now she needs to find Coyote, which isn't as easy as it may seem ... After considering the future of her mechanic shop, Mercy is approached by a woman named Lisa to handle a ghost haunting the home of a rich man.
While taking a quick run during the full moon, Mercy and Adam's pack come across a ritual burial site with skeletal remains of four children.
They discovered that she was an ancient fae that hunted down naughty children to eat their fingers and toes and bury their bodies in the cardinal directions.
Meanwhile, Mercy's stepdaughter Jesse is having a tough time at school due to both the recent discovery of the burial sites and being the daughter of a werewolf.
After encountering a troll, Mercy takes a young boy into the packs' protection while declaring the Tri-cities their territory against all others.
Mercy learns of the legend of the Harvester, who travels by less-trodden paths and reaps the souls that are ripe with a great black scythe.
She works as an auto mechanic and deliberately annoys her neighbor Adam, keeping increasingly decrepit and dismantled cars on her lawn (For a good time call...).
Mercy grew up in Bran's (i.e. the Marrok, a name taken from King Arthur's round table) pack because her teenage mother did not know how to raise her, as she had no knowledge of the supernatural prior to seeing her baby turn into a coyote.
Joe Old Coyote was killed by vampires (who made it look like a car accident) because he had destroyed a nest prior to getting involved with Mercy's mother.
Bran warned her that he mostly only wanted her as a "Brood Mare" because she could bear him children, unlike female werewolves who cannot carry a child to term.
At that point she left the Marrok's pack and returned to live with her mother until graduating from college with a degree in history and later finding work as a mechanic for a grumpy old fae named Zee.