Baker Street Wiki
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"It was only one murder and Samuel abused me. I will be out soon."
―Adam to Sherlock, right before getting arrested [src]

Adam Kemper, a.k.a. "The Balloon Man", is a serial killer.



In 2005, a twelve-year-old Adam was on his way to school. He was approached by a man in a van, who Adam seemed to be familiar with. He told Adam he will drive him to school. Adam saw balloons in the back of the van. He told Adam he had explain that they're for his parents when he got in. After Adam got in, the van drove away, leaving the balloons behind.

While in Abbot's possession, Adam was allowed to watch TV and would on several occasions see his parents plea for Abbot to give Adam back. Though Samuel was unaffected by it, Adam fed off it. He would later turn the tables on Abbot and become his abuser. In 2007, he started working as The Balloon Man, finding targets through Samuel's job as an exterminator.

As the Balloon Man[]

Adam and Samuel's first official victim was Daniel Peters. He kidnapped Daniel and kept him alive for one day before killing him. His next victim was Kayla Jackson. He kept her alive for half a day before killing her. He kidnapped and killed an unknown third victim. Their body was never found.

In 2009, Samuel broke three vertebrae in his back, forcing him to quit his job as an exterminator. While Samuel was in surgery, Adam continued without him and kidnapped William Crawford as his fourth victim. He kept William alive for two days before killing him. After surgery, Abbott started working as a delivering man for the Investor's Post. Adam would start finding targets through people who get the Post, or their neighbors. The next two unknown victims' bodies were never found.

Meeting Sherlock Holmes[]

"Sorry, it's just according to that birthmark on his chin, you're quite right; This is not the man who took Adam Kemper back in 2005, this IS Adam Kemper."
―Sherlock after the police found Adam in his van.

He later kidnapped his seventh victim, Mariana Castillo. His van was later found and he was caught and taken in. It was quickly realised by Sherlock Holmes that the man not only would be too young to be the man who took Adam Kemper, but the man actually was in fact Adam Kemper.

Initially, Adam refused to speak with anyone, giving the vibe that he was actually a victim and not the actual Balloon Man. He only spoke to Sherlock, who felt he could connect with Adam better than anyone. He saw that Adam's hand cut and asked if the Balloon Man did that to him. Adam said he did not, and said that he tried opening a window in his room and that he cut himself when his hand went through the pane.

Adam was offered an immunity deal, where he would be unable to be processed for any crimes he committed "in consort" (i.e. together with) with Samuel Abbott. They found out where Abbott lived and raided his place, only to find balloons that say "Congrats" and a USB drive with a video on it. The video was of Abbott telling them that if Adam was not released to him by noon the next day, he would kill Mariana Castillo. Adam told them that he was forced to help by Abbott, and he wishes he hadn't. He finally agreed to sign the immunity deal and told them where Abbott was.

When the police showed up at Abbott's, he told them to apologize to Adam for him and shot himself in the head. After Sherlock had a look around, he saw two bedrooms: one with a just ratty old mattress and stained sheets and another with a king-sized bed, lamp, TV, etc. He saw a hole in the master bedroom's window and realised that Adam was actually the Balloon Man.

He went to visit Adam in his room and told him that he knew Adam, not Samuel Abbott, was the Balloon Man. Adam told him the story about how he turned the tables on Samuel and how the deal Samuel proposed between him and Mariana was actually his idea for a contingency plan in case he ever got caught. He asked Sherlock if he was there to kill him, which he found exciting, and left to brush his teeth and announce he would not be in the city for much longer.

The next morning, Sherlock met with Adam in the park to talk to him about his fourth victim, Billy Crawford. Sherlock knew that Abbott had back surgery during the entire time that Crawford was kidnapped, killed, and found. Adam reminded Sherlock that he had an immunity deal, but Sherlock told him that the immunity deal only helps with crimes that he committed "in consort" with Samuel Abbott, and he actually took Billy on his own. Sherlock saw police cars coming and left Adam to be arrested, but not before Adam warned him that, since it was one murder and he was abused by Abbott, he would not be locked up for long.

Modus Operandi[]

Adam and Samuel Abbott, his captor, targeted children. He would ordinarily capture kids of the families, or the neighbours of families, that Samuel visited through his job as an exterminator, then a delivery man for the Investor's post. He would capture them and chloroform them so they would not struggle, although he did not do this with Mariana Castillo, as he heard sirens and rushed, as well as leaving balloons behind that said "Thank you," just as Samuel once did with him, which nicknamed him "The Balloon Man," and put them in his vehicle, a decommissioned NYPD van repainted brown, and drive off. He would then watch on the TV for interviews that their families would do, pleading for him to give their child back. The more interviews the families did, the faster Adam got bored, and the quicker he killed and buried the children.


It is unknown what kind of person Adam was as a child, but after he was captured by Samuel, he became sadistic, feeding off the grief of his, and other victims', families. He was also very intelligent, as he was able to turn the tables on his captor, which he claimed was easy as Samuel had "an IQ south of 90." He was able to outsmart even Sherlock Holmes, by tricking him and the rest of the NYPD into thinking that Abbott was the Balloon Man, and that he (Adam) regretted helping Abbott with the other murders. He was also able to concoct a contingency plan with Abbott, in case he was ever caught, which would not only let him go free, but also give him immunity from prosecution for any crimes he committed with Abbott.

Known victims[]

  • Samuel Abbott (beaten and abused)
  • 2007: Daniel Peters (first victim; kidnapped, then killed and buried after a day)
  • Kayla Jackson (second victim; kidnapped, then killed and buried after half a day)
  • Unknown third victim (kidnapped and later killed; body was never found)
  • 2009: William Crawford (fourth victim; kidnapped, then killed and buried after two days)
  • 2010-2012: Unknown fifth and sixth victims (kidnapped and later killed; bodies were never found)
  • 2013: Mariana Castillo (seventh victim; kidnapped, then rescued)