"Sick Burn" is the eighth episode of Season Four of Fox's Sleepy Hollow. It was written by Joey Falco and directed by Darnell Martin. It is the fifty-seventh episode of the series overall, and debuted on February 24, 2017.
When internet sensation Logan MacDonald comes to town, a supernatural infection hits, via a viral video. Meanwhile, Molly has a frightening vision that could predict a bleak future. Can the team cure the curse before it takes over town?
Malcolm is listening to his employees singing. Two guards drag a man up to Malcolm and he greets his "old friend." They drag an elderly Ichabod up, and Ichabod asks if Malcolm wanted the death of democracy. Malcolm dismisses democracy as ineffectual, and says that he's learned that people are herd animals and don’t want to bear the burden of governing themselves. He says that most people want a shepherd, and the guards drag Ichabod away.
Jobe wakes Malcolm up, and Malcolm says that he had another vision. He staggers to his feet and says that his vision was spectacular. He assures the demon that he is destined to become the best thing that has ever happened to America.
At an auditorium, Ichabod tries to record a selfie video and Molly gives him instruction. She accidentally knocks the phone out of his hand, and apologizes for breaking it. As Ichabod tries again, Molly takes the phone and steps aside to post it to Ichabod's Pictagram account. Diana thanks Ichabod for coming, and Molly rejoins them but says that it's pointless because Ichabod has no followers. Ichabod ponders what the world be like if Jefferson and Lincoln had the Internet, just as Internet sensation Logan MacDonald arrives. As the other fans gathered crowd Logan, Ichabod and Diana agree that Logan's Internet diatribes are boring. As Molly defends Logan, Logan overhears her and comes over. he takes a selfie with her... and then collapses. As Logan's assistants take him away, Ichabod sees Logan's arm glowing red. Diana takes Molly home while Ichabod investigates further.
When Diana and Molly arrive home, they find Jenny setting up security cameras and mystic wards. Molly goes to check on updates about Logan, and Diana tells Jenny what happened. Jenny offers to stay with Molly while Diana goes to the hospital, and admits that she'd like to know Molly better. Diana hesitates and Jenny says that they can't treat Molly with kid gloves. After a moment, Diana agrees and leaves.
At a bar, Alex's date Brad is trying to show her an Internet video. Jake is down the bar ordering a drink, and he chats with the bartender Missy. He insists that he and Alex are just friends, and they came on Tinder dates and they agreed to come to the other's help if their date was too much. However, Jake's date stood him up. Meanwhile, Alex tells her date that he's creepy and starts to walk off. Brad gets up to go after her... and collapses. They take him to the hospital and spot Ichabod. Ichabod explains about Logan's seizures and Alex says that they saw a guy with the same symptoms. As he goes to check out Brad, Brad screams and says that he hears his call, and then burns up... taking the attending orderly with him.
The team goes to the vault and Diana calls the CDC. They've been receiving similar reports around the DC area, and another victim burst into flames and burned down a whole hospital wing. Ichabod suggests that a similar affliction hit DC before and tells Jake to look for the works of Paul Jennings. He then tells Alex and Diana that when the British forced invaded DC, they burned down dozens of buildings. Paul Jennings was a young servant and White House slave. Jake finds a journal by Jake, which describes how pamphlets were handed out hours before the British attacked. Anyone who read the pamphlet came down with the illness. Paul and the White House staff dealt with the infection, which they named "influenza incendio."
Paul was the only one who understood that the disease was spread by cursed pamphlets, and spread by language. Alex figures that the disease was spread by Pictagram feeds, embedded in the source code. Diana realizes that Molly might be afflicted and calls her, and Jake and Ichabod agree that Malcolm is spreading the virus. However, Ichabod says that they have to focus on containing the infection. Meanwhile, Diana reaches Molly, who says that she and Jenny have been at Jenny's trailer and she hasn't watched Logan's videos. Relieved, Diana talks to Jenny and explains about the virial video. She asks her to make sure Molly is nowhere near computers and phones.
Once Diana hangs up, Jenny shows Molly the ancient Buddhist ritual of finding one's right path. She has Molly close her eyes and meditate. Alex goes to get some water, and Jake approaches her. He realizes that she watched Brad's video, and she shows Jake her glowing wrist.
Diana and Ichabod go out on the street and see hundreds of people watching their phones. Ichabod yells at everyone to turn off their phones because they're dangerous. The people ignore him, and one man stops an infected victim from walking out into traffic. The glow on her back forms a triangular pattern. Before Ichabod and Diana can get there, the woman bursts into flames.
In the vault, Alex says that she has to get out before she burns the place down. She figures that she has five more minutes before she burst into flames like Brad did, and Jake refuses to let her face it alone. Alex looks herself in the tunnels just as Ichabod and Diana arrive. Jake tells them what happened, and Alex calls and tells them not to come after her. She hears a voice calling to her, saying that it needs her, and she goes after it.
Ichabod tells Jake that they need his research skills and he has to focus. Jake agrees and Diana describes the pattern they saw on the victim. The symbol contained Arabic writing, and Jake realizes that he knows the symbols. He checks the Histories and finds a book with the symbol on the cover. It contains more of Paul's writings, and realizes that he worked with a team at Vault 355. The other team members were Sam Wilson, Davy Crockett, and Sacajawea. Paul determined that a djinn was responsible for the symbol, and Jake warns that the djinn were powerful demons of fire. The curse transmits the symbol onto the victims, and they are compelled to find the djinn's lair and then it consumes them in flames. Ichabod tells Jake that Paul and his team stopped the curse by Sam reading the curse. The others followed him to the djinn's nest and Paul summoned a tempest to strike down the djinn with lightning. Sam didn't survive the infection, and Jake vows that Alex won't suffer a similar fate.
The victims--including Logan gather at the djinn's lair: a server farm. It says that they must all burn for it and joint he eternal flame, and consumes one victim. Alex is among them, saying that she is ready to burn with it.
At the trailer, Jenny explains to Molly that August showed her the ritual. She assures the girl that there is no wrong choice, and all of the paths have value. Molly takes a bowl, and Jenny explains that she chose a crossbow: the path of a warrior. The bowl represents the path of the oracle. Molly strokes the bowl's rim and then has a vision of an elderly Ichabod imprisoned in a cell. The girl snaps out of the vision and tells Jenny what she saw.
Diana gets a serum from Jenny's alternative medicine cabinet and puts it in a syringe. It will cause a rapid drop in body temperature. Meanwhile, Jake says that he was unable to trace the video's source code. Ichabod says that he must infect himself and lead them to the djinn, and tells them that he has a responsibility to witness the curse and ward off evil. However, Jake says that he's already looked at the video twenty minutes ago. He figures that it was the fastest way to track Alex down, and says that Alex would have done the same for him.
The trio goes to the car, and Jake has an attack. He then tells Ichabod and Diana that he knows where Alex is. he takes them to the server farm where the djinn is and tells them to get Alex out and ignore him. They go in and find hundreds of infected victims. They spot Logan and make their way through the crowd... and Alex. She approaches the djinn, and Jade is consumed by the infection. Diana infects Alex while Jake shrugs off Ichabod and goes to the djinn. It throws a fireball at Diana, who ducks just in time.
Ichabod dons a pair of insulated gloves, rips free two electrical lines, and says that it's time to summon the lightning. The djinn comes at him, and Jake reaches for it. Alex runs up and knocks Jake aside, and Diana shoots the djinn. Distracted, Ichabod is able to electrocute it. everyone snaps out of the spell, and Jake and Alex confirm that they can't hear the djinn's voice.
Later at the vault, Alex thanks Jake for saving her. She says that no one has ever risked everything for her before, and Jake figures that she'll pay him back. Alex hugs him, just as Ichabod and Diana come in. Jenny arrives as Jake puts up a painting of the original Vault 355 team. He figures that they're the descendants of real heroes. Diana points out that Ichabod doesn't seem himself. He finally shows her a letter from George appointing Ichabod as commanding officer of Vault 355. Ichabod worries that his war on evil will get one of the team killed, and Diana tells him that it's a burden of leadership. Ichabod goes to the others and suggests that they celebrate victory with a commemorative selfie. They all say "prunes" and take the picture.
Diana asks Jenny how it was taking care of Molly. Jenny explains about Molly's vision of Ichabod in the future, and warns that something is coming. Ichabod overhears her and says that someone is coming: They figure that Malcolm summoned the djinn, and Ichabod wonders why.
Jobe tells Malcolm that Ichabod and his team contained the outbreak. Malcolm tells him that there is nothing that they can do to stop the future that he's seen. He's assembling a team of his own, and says that he got everything he needed from the outbreak. Logan comes in and Malcolm says that he's their Patient Zero. The youth says that he can feel himself becoming something stronger, and Malcolm tells him to be patient for the others to arrive.