Chilling Plans on HBO Max: The Story Behind Frank Olson's Death and MKUltra
The third episode of the documentary series Horses & Hangmen investigates the failed assassination attempts and the CIA's involvement in the biochemist's downfall
What is the series about?
Chilling Plans is the third episode in the HBO Max documentary series Horses & Hangmen, which premiered on September 12, 2025. The series delves into some of history's most complex and dark criminal cases, and in this specific episode, the focus is on biochemist Frank Olson. Through archival footage and reconstructions, the episode explores the 40-minute narrative of how a high-ranking scientist in the U.S. defense ended up as a victim of his employer's secret experiments.
The episode particularly focuses on the psychological aftermath for Olson's family when they received the official confirmation of his death, as well as the shocking police investigations of several failed assassination attempts that allegedly took place prior to his fatal fall from a hotel window in New York. The documentary is available in several languages, including Danish, and serves as an important piece in understanding the Cold War's most controversial programs.
The real case
The real case of Frank Olson began in November 1953. Olson worked for the U.S. military's biological weapons laboratory at Fort Detrick and was associated with the CIA's top-secret MKUltra program. During an informal meeting between CIA agents and scientists, Olson was dosed with the psychedelic drug LSD without his knowledge or consent. The purpose of the experiment was to investigate the drug's potential as a tool for brainwashing and interrogation.
Nine days after the incident, Frank Olson fell to his death from the tenth floor of the Statler Hotel. Authorities quickly determined that it was a suicide caused by a sudden psychosis. It was not until decades later, in 1975, that the truth about the LSD experiment emerged through the investigations of the Rockefeller Commission. Read more about the MKUltra program here . The case was reopened in the 1990s when Olson's family had a new autopsy performed, which showed signs of blunt force trauma to the skull that occurred before the fall, raising suspicions of murder rather than suicide.
Timeline of the case
The case of Frank Olson spans over 70 years and involves both secret government documents and private investigations. The investigation into the assassination attempts described in the documentary paints a picture of a man who had become a security risk for the intelligence agency.