Letharia Vulpina is the 19th episode of Teen Wolf Season 3.

The episode is named for a type of fungus that is commonly used to poison wolves and foxes.


Scott and the others try to prevent a disaster; Lydia and Allison seek out an unlikely teacher.

Full Recap

A group of Yakuza are gathered at their boss Ikeda's home. He is angry because his pet white wolf is sick and he grows tired of waiting for the doctor.

It is Dr. Deaton who comes to treat the wolf. After a brief examination he asks if the wolf, Yuki, has been around any unusual plants. He describes a type of lichen that is “bright green, almost neon.”

The boss admits that such a plant grows in his garden. Deaton says he needs a sample to determine the species. When all of his men refuse to show the doctor to the garden, he calls them superstitious idiots and takes Deaton himself.

The garden is the same one where young Chris Argent first encountered the Oni. The lichen grows on top of the fountain where the blood fell when the Nogitsune was killed. Deaton hands a glass container to the boss, then bends down to take a sample of the plant. He says it is likely that Yuki would never come anywhere near the place. He says the wolf can sense what happened in the garden, to the boss’s father and the nogitsune that possessed him.

The boss pulls a gun on him. Deaton is nonplussed and calmly explains that the plant is Letharia Vulpina or “Wolf Lichen” and describes the process by which it is used to kill predators, wolves and foxes. He says “they” would put out meat stuffed with the lichen and broken glass that the animals would eat. The broken glass would perforate the internal organs and allow the vulpinic acid to reach them faster.

EDITOR’S NOTE: Deaton’s explanation of how animals can be poisoned with Wolf Lichen is historically accurate according to the 1921 text Lichens by Annie Lorrain Smith.

Angry and confused, the boss wants to know what Deaton did to his wolf. The doctor says he gave him a strong paralytic agent and that the glass vial the boss is holding is coated with the same substance. The boss drops the gun, his hand no longer able to hold it, and collapses.

As he places his sample into the bottle, Deaton explains this particular plant is quite special because it was born out of the blood of a nogitsune. Deaton says “there is a fox hiding inside a teenage boy and I’m going to poison it.”

A sparking power line from the roof of Beacon Hills Hospital is flying at Kira’s face. It whips past her but then, like it has a mind of its own, it seems to chase her, backing her up in the parking lot. An ambulance speeds around the corner and hits the electrified line. The driver loses control and rams a fire hydrant, water sprays everywhere and begins to pool and run across the parking lot. Dazed by the impact, the ambulance driver stumbles out of the vehicle. When his foot hits the wet ground he is instantly electrocuted. Issac and Allison arrive just in time to witness this. When Allison runs forward to help the driver, Isaac pushes her back just as the water reaches his feet. He is also felled by the electrified water.

"Die on Teen Wolf" Contest winner Katie Myers steps from a car and is electrocuted. Derek and Scott arrive just as Kira somersaults over a car and grabs the live wire. She caps the sparking end with her free hand and the power subsides as her eyes begin to glow warm amber. Kira's Mom exits the hospital just in time to witness her daughter’s power. Derek rushes to Isaac and finds he is not breathing.

48 hours later, Scott is in bed fully clothed. He remembers the events of that night again. A badly burned Isaac is rushed into the emergency room. Deputy Parrish reports that Stiles’ Jeep was seen leaving the hospital. Kira’s mom warns her that it “is not the time” for people to see her power. Agent McCall notes that the power line was cut and warns that everyone should be looking for signs of sabotage. Derek tells Scott to tell Sheriff Stilinski what’s really wrong with Stiles.

Melissa McCall holds a cup of tea at the kitchen table when her son comes in. She explains that they've still not found Stiles after 48 hours. She says, despite how long he’s been gone, if anyone could be missing for two days then turn up and be just fine - it would be Stiles. They decide to stop by the hospital on the way to school to check on Isaac.

Sheriff Stilinski is looking at a text from his son. It reads – “Am ok. Please don’t look for me. Be back soon.” Deputy Parrish arrives with a delivery man, he has two boxes wrapped in brown paper which Parrish explains are “printer cartridges and stuff, batteries for the next blackout.” Agent McCall enters and asks if the Sheriff has had any problems with Yakuza.

Allison has fallen asleep in the hallway of the hospital. She explains to Scott and Mrs. McCall that they won’t let her in to see Isaac because she is not family. She says she told them that he doesn’t have any family. Melissa says “he’s got us” and produces her key card and lets Allison and Scott in to see him.

Isaac is badly burned on the side of his face and neck. Both Allison and Scott are surprised that he is not healing. Scott takes his arm and absorbs some of Isaac’s pain. He explains that it won’t heal him but he won’t hurt as much. Allison wants to know if Stiles is really responsible. Scott says whatever is inside of Stiles did it and that he is working on getting it out of his friend.

Later at school, Kira explains that Kitsune are tricksters and have no concept of right or wrong but that Nogitsune react badly if you offend it adding that with the level of bad being perpetrated, someone really, really offended this nogitsune.

Coach blows his whistle and reminds his team that if anyone sees Stiles they should immediately report it to a teacher. He then says there is a card for Isaac on his desk. He insists that the team not only sign the card but each must write a personal message so profound and deep that it will “bring a tear coach’s eye.” Danny is first up to sign. The coach warns him to keep it “PG.”

The twins report to Scott that they've not seen Stiles or the “Demonic Ninjas” (Oni). At that moment their werewolf hearing picks up the piercing tone of one of Chris Argent’s ultrasonic emitters. They follow the sound to the basement where they find Stiles waiting. The twins attack until Scott forces them off, throwing Ethan against a locker and then growling Aiden into submission.

Stiles explains that he doesn’t know what he’s been doing for two days. He has a blueprint of the hospital electrical grid and a bag full of rope, wire and tools as well as a map of the Cross Country Team’s running trail. The trial is the same area where Malia Tate lost her family in a car wreck and where her father put out a bunch of metal bear traps in an attempt to catch the werecoyote. Believing the nogitsune has used Stiles to set up booby-traps along the trail, the trio race to stop the team.

Lydia sees her mom down at the end of the hall in school. She is talking to Peter Hale. As she draws closer Peter disappears in the crowd. When questioned, Lydia's Mom says Peter claimed to be from the health department and was there to set up hearing tests for the students. He also apparently slipped Mrs. Martin his phone number to which she chirps “still got it.”

Chris Argent returns home to find his door ajar and an ultrasonic emitter stabbed into the top of his office desk. Derek Hale is in the room. He knocks the gun from Argent’s hand and places his claws against his neck. Chris pulls another gun and holds it to Derek’s temple. Derek accuses Argent of leaving the emitter in his loft. An uneasy truce is established and the weapons are put away.

On the trail, Danny takes the lead but is passed by a gleeful Kira who suddenly realizes that she can run supernaturally fast. Stiles and Aiden catch up to Coach at the start of the trail.

Argent realizes that one of his cabinets has been forced open. Inside there is a metal briefcase, after checking it for a trap, they open it and find $150 thousand dollars. It is the money that would have come from the sale of his antique gun to Silverfinger. At that moment, Agent McCall comes in with the prosthetic silver finger in an evidence bag and says the old Yakuza is dead.

Ethan catches and tackles Danny who is confused until the weretwin says he “missed” him and starts kissing him. Scott manages to stop Kira who is still giddy with her speed ability. Stiles Coach and Aiden arrive and they manage to stop the rest of the cross country team. Stiles finds a chain under some leaves but it is attached to nothing. Coach, believing this is just another funny/weird Stilinski moment begins to berate him and steps forward into a tripwire. An arrow punctures Coach’s diaphragm and he collapses.

Allison and Lydia arrive at Derek’s Loft to see Peter. Allison is trying to talk her friend out of it but Lydia, worried about her recent “colossal failure” in using her Banshee abilities, wants the help Peter is offering. Allison says Peter doesn’t offer help, he offers to manipulate people into giving him what he wants.

On the trail Coach is screaming. Stiles is pushing on the wound in his stomach which has spread blood all over his shirt. The arrow is still in there and the coach is screaming for someone to pull it out. Stiles gives Scott a look indicating he should use his ability to take away pain. Scott does so and Coach passes out.

Derek and Chris are handcuffed to a bench outside Sheriff Stilinski’s office. They discuss why Stiles would want to frame them for murder. Chris says he’s not entirely convinced that’s what is going on and comes up with a scheme to buy more time to figure it out. He asks Derek to say that he wants Argent’s attorney to represent him as well.

Peter wants Allison to leave. Lydia says she stays because the last time she was alone with Peter she almost bled out on a lacrosse field. Peter defends himself, explaining again that he didn't want to kill her because she was his “backup plan” and then claims that the bite is what brought out her nascent abilities. Then, in a passable Humphrey Bogart accent, Peter says “I’m the spark that lit your fire sweetheart.”

He then uses circular logic to suggest that he brainwashed her and used her to bring him back to life so that he could be here now helping her understand her banshee abilities to which Allison says “he’s insane.”

They turn to leave but Peter entices them back with information about her powers. He says her Banshee scream simply blocks out all the other noise so she can hear what she really needs to. He says that he can help her focus her hearing.

He explains that in exchange for his help he needs Lydia to listen to his dead sister’s claws to find out what memory she stole from him.

Coach gets put into an ambulance and Sheriff Stilinski finally gets to hug his son. Aiden discovers wrapping paper in the back of Stiles’ Jeep. Remembering that William Barrow used a giftwrapped package to deliver his bomb to a school bus, they call the school and evacuate all the kids off the busses – all but one.

Jared (last seen in Frayed where he vomited on a school bus) is sitting near the back of the bus.

Deputy Parrish insists that he can safely get a look at what type of bomb they’re dealing with because he was “certified HDT” after two years in the military.

EDITOR’S NOTE: HDT stands for Hazardous Device Team.

Lydia holds Talia’s claws. Peter says she needs to focus but says he can “see the wheels spinning” behind her eyes. He explains that her hearing is attuned to a level of the universe that no one else can hear. But it only works if she is listening. When he yells at her to try harder, Allison whips out the electroshock/cattle prod device. He pops his claws and says Aunt Kate had the same thing but it didn’t help her when he slashed her throat.

Lydia screams at them to stop and throws Talia’s claws so hard they stick into a wooden beam like darts. She begins to hear whispering. Peter grows more and more agitated as Lydia listens to the voices. Finally she turns and says “you’re not just an uncle.”

Derek is annoyed and wants to break out of the cuffs. Argent says he could too but doesn’t want to be a fugitive from the law. He convinces Derek to be patient a little while longer. While Derek agrees he says that if something happens “don’t expect me to risk my life for yours.”

Mrs. Yukimura is waiting for her husband in his classroom. Kira is following him at a discrete distance. He enters, closes the door and retrieves a large History of the World book from a shelf. She is incredulous that he “hid them in a book” but he says it’s the safest place around a bunch of teenagers because few would ever “willingly open a book.”

Inside the pages have been cut to create nine slots. Each is designed to hold a single black knife. Mr. Yukimura tells his wife that she needs to tell Kira “especially about this” indicating the book. He says she has already “sacrificed five.” He says three of the Oni are gone then asks “how many tails are you willing to sacrifice?” She says all of them if she has to.

She then removes one of the knives, about a foot in length, all black with a rectangular hilt. She snaps the knife in two causing her husband to wince as if in pain. A pale blue light escapes the two broken pieces of the knife. She lays the pieces down and repeats the process with a second knife. She says “these Oni will be stronger, much stronger.”

Parrish enters the bus and tries to keep Jared calm while he checks out the wrapped package. Jared is sweating profusely and Parrish admonishes him not to throw up. He keeps talking to distract the boy explaining that he is 24 but still looks young and that anyone can look young if they eat right and exercise but that it really comes down to good genes. While he continues with this patter he has managed to snip the ribbon from the box. He slowly pries open the lid and looks inside.

Parrish radios to the Sheriff that it is not a bomb but that something else was in the box. He then walks to the front of the bus and holds up the nameplate from Sheriff Stilinski’s desk. The sheriff remembers the packages delivered to him that morning, realizes that the bomb is at the station.

The Deputies at the station are in a panic. They hastily unlock Argent and Derek’s handcuffs and run for the door. Derek seems to hear something coming from the box on Stilinski’s desk and yells for Argent to get down then covers him with his own body to shield him from the blast.

At the school, Mr. Yukimura and his wife watch as the sun sets. At the Nemeton, fireflies erupt from the magic stump. These are slightly different than the ones seen before. There is a blue, slightly metallic, sheen to their wings.

Inside the Sheriff’s Station, Stilinski is calling for an ambulance reporting “multiple officers down.” Derek’s back is riddled with glass shards as Argent helps him stand. Derek says he’s okay, Argent points out that Derek saved his life.

Stiles and Scott kneel by one badly injured deputy. Stiles encourages Scott to take the dying man’s pain, which he does until the man expires. Kira runs in and tells them that the Oni are coming.

They plan to take Stiles to the Vet Clinic since it is lined with Mountain Ash and will offer some limited protection from the Demon Warriors.

Lydia denies knowing anything beyond the fact that Peter is a father. Peter makes to physically threaten her but Allison jabs him in the back with the cattle prod and he is left writhing on the floor. Later, in the car, she and Allison each pull up a different image on their phones. One is of Peter the other is Malia Tate. Lydia says Malia is Peter’s daughter.

Scott, Stiles and Kira arrive at the clinic just before the Oni. Scott and Kira fight them off while Stiles unlocks the door. During the fight one of the Oni stabs Scott in the stomach, leaving the sword lodged in him. They manage to get Scott inside but then Stiles grabs Kira’s arm and slams her head into the exam table, knocking her out. He then grabs the hilt of the sword and twists.

Nogitsune Stiles explains that he feeds on pain and misery and that he’s been manipulating Scott to soak up as much pain as he could all day just so he could feed. Then, placing his hand to the side of Scott’s head, he absorbs all the pain Scott has taken.

Then, all smiles, Nogitsune Stiles says Scott really has to learn “not to trust a fox because they’re tricksters. They’ll fool you.” while in flashbacks we see that the nogitsune showed its true face in Stiles' expressions several times throughout the day.

He finishes by saying “They’ll fool everyone” at that point Deaton steps up and says “not everyone” then injects a syringe (with wolf lichen) into Stiles’ neck.

The nogitsune collapses on the floor.

Deaton pulls the sword out of Scott and explains that he poisoned the fox but “it’s not dead, not yet.”


  • William Fitzsimmons - "Hold On"

Scene: Scott talks to Melissa.

  • DANK - "Renegade (Radio Edit)"

Scene: Cross Country practice starts.

  • Thrillseekers - "Dreaming of You (Dub Mix)"

Scene: Scott and Kira share a moment.

  • BASECAMP - "2 Thingz"

Scene: Allison and Lydia visit Peter.

  • Cameron the Public - "Apple Pie"

Scene: Coach Finstock gets shot by an arrow.



Episodes List

Season 2 Season 3 Season 4
#01 Tattoo #07 Currents #13 Anchors #19 Letharia Vulpina
#02 Chaos Rising #08 Visionary #14 More Bad Than Good #20 Echo House
#03 Fireflies #09 The Girl Who Knew Too Much #15 Galvanize #21 The Fox and the Wolf
#04 Unleashed #10 The Overlooked #16 Illuminated #22 De-Void
#05 Frayed #11 Alpha Pact #17 Silverfinger #23 Insatiable
#06 Motel California #12 Lunar Ellipse #18 Riddled #24 The Divine Move
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