An FEV subject immediately after expiration. Results such as this were common in FEV experimentation.

Operation Mariposa (Eurasian: Operatio Mariposa; Lyrian: Betreib Mariposa), also known as the Forced Evolutionary Program (Eurasian: Programma Coactiva Evolutiva; Lyrian: Erzwungenen evolutionären Programm) was a series of genetic and biological experiments conducted by the Empire of Eurasia and Duresia during the Great War and after. The experiments were designed to engineer a series of superhuman soldiers and test biological and chemical weaponry. The operation is thought to have been active from 1942 to around 1966, with a brief sabbatical period following the abdication of Laurentius III due to the military and political reshuffling that commenced with Marinus ascension.

The program is widely considered one of the most horrific ever conducted by any nations, and the results are still highly classified by both Eurasia and Duresia, with what is known only being known thanks to whistleblowing efforts by third-party hackers and informants. The program is believed to have operated under the guise of a work-visa program in Zackalantis and Newellia, which by that period had transformed into the Khanate. The program enticed poor Zack of Khan peasants to sign up for work programs in Eurasia and Duresia, whereupon they were promptly kidnapped and shipped to bases located far in the northern arctic, in Tergeste, where the experiments were conducted.

The experiments included the use of the Forced Evolutionary Virus, which was meant to induce rapid mutation in human subjects to increase muscle mass, bone density, and suggestibility. Many of these experiments failed outright, whilst others resulted in horrific mutations and deaths. Experiments were also conducted on the capability of humans to survive in vacuum and in space, and many attempts were made to launch the first man into orbit, until Duresia finally succeeded in secret in 1960 and then publicly in 1961.

FEV Trials

The most renowned segment of Operation Mariposa was the FEV Trials, which were a series of experiments, divided into three phases and ending in the disastrous Catacomb 87 Incident, in which kidnapped Zack and Khan citizens were subject to exposure to the virulent Forced Evolutionary Virus (Eurasian: Virus Evolutivum Coactivum; Lyrian: Erzwungenen evolutionären Virus). The intention of the projects was to create an expendable and controllable breed of supersoldiers that could be utilized in protracted warfare against enemies of Eurasia and Duresia. The experiments all ended in failure.

Phase I

The initial phase of the program involved the exposure of the test subjects to FEV I, the initial iteration of the FEV virus. This was done via injection, but after the initial subjects failed to develop in any meaningful way, the first aerosol chambers were developed. Around 150 Zacks and 150 Newellians were involved in this phase of the experiment, all of whom passed away due to complications from the virus. A Eurasian scientist wrote in the official records:

Each subject experienced largely the same progression. Stupendous physiological growth, followed by multiple organ failure and death. It appears the forced development brought about by the virus is too rapid for the subjects' bodies to allow. Recommend development of a different FEV strain.
— Dr. Titus Maurellius Decimus

Phase II

Phase II was larger than Phase I, and involved the development of FEV II. It was far more effective as a viral agent, and allowed rapid development of the test subjects. Medical records indicate that the issue of organ system failure was resolved by increasing the time during which the subjects developed, allowing for far greater strength and physiological resistance to be gained. The records further indicate that the FEV caused almost immediate, unbearable pain, followed by a period of rapid physical development. Muscles grew rapidly and exponentially, the skin hardened drastically, and all indications of external genetalia or sex effectively transitioning the subject to an asexual state.

Some subjects during this period were kept in medically induced comas, while others were kept awake via amphetamines, and still others were given no psychoactive medication. Analgesic medication was, as far as records indicate, never distributed. It appeared that in many cases FEV caused severe inflammation of the pain center of the brain, namely the thalamus, insula, and the dorsal anterior cingulate cortex. This caused many subjects to be subject to nearly incalculable amounts of pain and agony.

Phase II, however, hit a similar roadblock as Phase I. The subjects organ systems remained functioning, but the immense pain and FEV-induced damage to the brain caused most higher-level cognitive functions to rapidly fail, and most subjects expired due to a failure of the cerebellum. In effect, the FEV so damaged their brains that even basic functions like breathing and heartbeat were impossible. Thus, a newer strain would be required.

Phase III

Phase III was the most successful part of Operation Mariposa. Working from previous failures, the scientists developed FEV III, which it was hoped would lessen neurological damage to a manageable degree. It was thought that, even if the subjects were to mentally damaged to sustain higher cognition, they would be cognizant enough to follow basic orders and use weaponry, making them exceptional disposable soldiers. This in mind, Phase III was deployed.

Success was almost immediate. The first subjects exposed underwent the painful mutation process that the previous iterations had, but did not generally succumb to neurological failure. However, their higher-level reasoning was so damaged they did not recognize the scientists or legionaries as friendly and attempted to attack them. Many subjects were either forcibly terminated due to this disobedience, died due to the brutal mutation process, or were sealed in their test chambers for further research after the conclusion of Phase III.

Though, ultimately, Phase III could be considered a scientific success, the program was ultimately abandoned following the Catacomb 87 Incident, in which an FEV-exposed test subject escaped containment and accidentally released FEV into the entire facility, resulting in termination of the project.

Catacomb 87 Incident

The Catacomb 87 Incident was an incident which took place as part of Operation Mariposa, which resulted in the deaths of numerous Eurasian and Duresian military personnel and the end of the FEV trials. The incident occurred in the isolated Catacomb 87, which was one of a series of military installations designed to be part of Operation Mariposa and was designed to hold the FEV testing facilities of Phase III. The incident occurred when one of the FEV subjects, called TS-44, was accidentally freed following a power distribution accident, and caused a massive disruption of the FEV distribution systems, contaminating a large portion of the FEV testing facilities and causing many of the science staff and uninoculated test subjects to undergo rapid mutation. They quickly freed captive mutants, and soon there was a full-scale mutant revolt ongoing.

The Eurasian and Duresian militaries temporarily managed to seal the contaminated sections and purge the air filtration systems of the FEV, but the mutants forced their way through the sealed sections and quickly overran the majority of the facility, forcing the military cordon into retreat where they sealed the facility. Following the facility's sealing, several military teams re-entered the facility to retrieve remaining information, and finally to purge the remaining FEV reserves, before the facility was again resealed and a perimeter set up around the facility, before it was ostensibly destroyed in a hastily arranged nuclear test in 1967.

The facility itself is said to be destroyed, which is maintained officially by the Eurasian and Duresian Governments. However, the Eurasian military did maintain and still currently maintains a strictly enforced militarized perimeter, and no reporters nor researchers are ever allowed in. Unauthorized entry into the area is considered an act of High Treason in Eurasia and, peculiarly, in Duresia as well.


The legacy of Operation Mariposa is complicated. Classified by Eurasia for more than half a century, it was only revealed following the work of whistleblowers and activists working in New Zealand and Zackalantis in 2017. The Eurasian Government responded immediately, arresting three of the Eurasian-born activists and executing them for High Treason on live television. The Ministry of the Frumentarii also initiated a widespread disinformation campaign and forcibly shut down many websites carrying leaked documents. Nevertheless, the information persisted. Eurasia has never publicly acknowledged the project, and has vehemently denied it to the international community, as has Duresia.