- "Mary tracked the demon to a farmhouse, where she managed to seal it in an underground chamber. Years later, members of this very agency reinforced her mystic barriers by constructing a protective totem on the selfsame spot."
- —Ichabod Crane
John Wilkes Booth was the demon in question who debuted in the Season Four premiere, "Columbia", and the first monster featured in Season Four.
Merging with a DemonEdit
John summoned the demon into his body by using black magic. The demons was summoned to help destroy the Union. Over time, the American flag became a trigger that activated the killer instinct within the demon. During a play, John saw an American flag and ended up killing Abraham Lincoln. But Mary Todd Lincoln, sealed the demon away in an underground chamber after her husband died under her husband's statue in the Lincoln Monorail. 
Hundreds of years later, the demon was released when Lincoln’s head was chopped off his statue. Since then it was able to create those strange green holes, and caused two murderers, including Diana's partner, Eric. He was described as a monster with stringy hair and wearing 19-century garb. When Ichabod and Diana first discovered The Vault, they realized that he had once summoned the supernatural in order to make Lincoln's death successful. Ichabod determines the demon was raised back in 1865 by John Wilkes Booth who used it to kill President Lincoln. Booth summoned the demon into his own body, however, Mary Todd Lincoln – who apparently was aware of demons and tried to keep her husband safe – ultimately sealed the demon in an underground chamber following her husband’s murder. That chamber is under the Lincoln Memorial, and the demon was released when Lincoln’s head was chopped off his statue. According to Alex and Jake, the monster is weak against copper, and the American flag is the trigger. He actually described these things as "the demon's Kryptonite". Diana figured copper is its weak point because its cell walls were made of copper. The flag was actually the reason why the demon was summoned in the first place, to destroy the Union and Lincoln himself. During a patriotic parade, Ichabod leads John away and ambushes the new pair. Thankfully, Jenny rescues them in the nick of time by firing a few sharpened pennies. However, Malcolm, who had obtained the Lincoln Head. With the help of Jobe, his bodyguard, he destroyed it with his laser eyes and it revealed a circular tablet. 
- Enhanced strength: He may also have unsurmountable strength as it tried to strangle and kill Jake.
- Enhanced speed: Since then, it was indicated that the single vessel has outrageous speed. A perfect example was during the parade as it outran Ichabod and Diana and immediately caught up to Jake.
- Magic: Through black magic, the demon merged with John Booth's body.
- Copper: Despite the creature's capabilities, it can be imprisoned and killed by copper.
- There is a fact that the main protagonist of Bones, Seeley Booth, is actually the direct descendant of John Wilkes Booth.
- The decapitation of the Lincoln Memorial was very significant. It was a somewhat reoccurrence of the real John Wilkes Booth who was widely known as Lincoln's killer. On April 14, 1865 at the Ford's Theatre, he shot him at the back of his head. He also had a band of conspirators to carry out the plot, which was originally the abduction of Abe. This was similar to Ichabod's findings of him summoning demons who threaten to kill Washington's highest officials.
|"Columbia"||"In Plain Sight"||"Heads of State"||"The People vs. Ichabod Crane"||"Blood from a Stone"|
|"Homecoming"||"Loco Parentis"||"Sick Burn"||"Child's Play"||"Insatiable"|
|"The Way of the Gun"||"Tomorrow"||"Freedom"|