- "Even your most destructive weapon would barely register as a blip on my radar. Know this -- you mortals will not claim the shard. It is I who will enter Agartha. I am the new dominant life form on this world."
- — Avogadro after the nuclear explosion
Cornelius Pernell (also known as Avogadro) is a character featured in Treyarch's Zombies mode, and leader of Broken Arrow. Pernell originally appeared in a radio on the map Shi No Numa from Call of Duty: World at War. Pernell is also mentioned in the CIA Data servers from Call of Duty: Black Ops where the transcript of his transmission to Peter McCain can be found in the Vbush files.
Pernell made an appearence in a radio on the map Revelations from Call of Duty: Black Ops III as Cornelia, an alternate universe counterpart. Pernell can also be heard in several radios and audio logs on the maps Classified and Alpha Omega from Call of Duty: Black Ops 4. In Alpha Omega, it was revealed that a fragment of Pernell became the entity known as Avogadro already seen on the map TranZit.
Cornelius Pernell was a member of the OSS during World War II and the handler of several operatives. He successfully led the operation to infiltrate Peter McCain in Group 935 and Peter was transfered to the Asylum Facility in Berlin. Suspecting that the Group 935 was losing control over their experiments, Pernell sent a Marine recon unit on August 1945, the team was led by "Tank" Dempsey.
An outbreak occured shortly after in the Asylum Facility and Peter, who was ousted as a spy, managed to escape. The recon team faced hordes of zombies inside the asylum, the team was killed and Dempsey was ultimately captured by Group 935. On September 1945, Pernell attempted to contact Peter McCain to rendezvous at the Rising Sun Facility under the control of Group 935 and Division 9. The next month, Peter parachuted over the Rising Sun Facility and died shortly after.
In 1961, construction began at Groom Lake for a teleporter to establish a link between the facility and Griffin Station on the Moon with Pernell overseeing the project. The next year, Pernell started overseeing the construction of the American Pyramid Device at the nuclear testing site in Groom Lake.
On February 1963, Pernell learned about the existence of Samantha Maxis from Doctor Schuster. After months of research, he was convinced the US Government would need even more Element 115 to fight Samantha and he would be able to securing the funding for his program he dreamt about for many years, Project Broken Arrow. On August 3rd, 1963, while new tests were performed with the teleporter, the Ultimis crew (Edward Richtofen, "Tank" Dempsey, Nikolai Belinski and Takeo Masaki) was teleported from the Moon and arrived at Groom Lake. After medical examination, Cornelius Pernell kept the crew locked up in Hangar 4 as test subjects for Element 115 experimentations. Unfortunately for Pernell, Ultimis would escape with the help of their Primis counterparts a few months later.
After the Pentagon incident, projects from Broken Arrow focused on a targeted assault of Samantha were shelved. The A.P.D. was repurposed to be used as an interrogation tool for Project MKAlpha, as part of the Project MKUltra from the CIA. As such, more funding were provided to ensure the construction of the A.P.D. was completed on schedule.
On June 1964, using the Elemental Shard, acquired from Division 9 in 1946, Pernell and Doctor Hale resurrected Peter McCain. Peter began working at Broken Arrow shortly after.
On February 1965, as part of Phase II of MKAlpha, Pernell began the interrogation of Yuri Zavoyski. Pernell learned from Yuri about the Aether and Agartha, but Pernell ended up killing Yuri in the process. Pernell began being obessed with reaching Agartha, and after years of exposure to Element 115, he started hearing voices similar to Ultimis Richtofen and grew increasingly paranoid. By 1966, he started having recurrent dreams, one of them showing him becoming Avogadro inside the A.P.D. using the Elemental Shard.
A year later, on August 1967, Pernell started experimenting on himself with the help of Dr. Hale, whose affection for him was well-known, by placing himself inside the A.P.D. and pulling an electrical current from the Elemental Shard to flood the A.P.D. The experiments continued until 1968. Peter, who became Deputy Director at Camp Edward, heard about the experiments and decided to file a report to George Sawyer against Pernell. Unfortunately for Peter, Pernell learned about the report and had him arrested.
On March 15th, 1968, Sawyer and his men arrived at Camp Edward during one of the experiments causing the facility to lose power transforming Cornelius Pernell into Avogadro. Avogadro released Nova 6 gas throughout the facility and unleash zombies and A.D.A.M. Units, killing everyone. This resulted in the full lockdown and abandonment of Camp Edward, and the shutdown of Rushmore.
Almost 60 years later, on July 2025, Broken Arrow agents Russman and George Barkley returned to the facility and used the A.P.D. to transfer a sample of Avogadro to the Hanford site in Washington state - this sample would go onto become the mindless Avogadro that was consumed by the Pylon as a power source for Ludvig Maxis.
Breaking The Cycle
Following the events at Alcatraz Island and having Rescued Ultimis from Hangar 04, Primis and Ultimis arrive at Camp Edward to retrieve the Elemental Shard, which results in the awakening of Avogadro and subsequent detonation of a nuke. Avogadro is ultimately defeated and forced back into the A.P.D, being sent to the Hanford site in Washington and allowing access to the Elemental Shard.
Avogadro appears on Alpha Omega as the boss at the end of the main quest alongside many A.D.A.M. Units. To defeat it, players will need to charge four back-up canisters located in the Lounge, Beds, Diner and Storage areas of the bunker. Avogadro will follow and attack the players during the process. Once a canister is charged, Avogadro will fill it with electricity for the rest of the game, dealing enough damage to down any player inside the room.
Once all the canisters have been charged, players need to go back to the APD Room and shoot Avogadro to push it back inside the A.P.D. Once close enough to the A.P.D, Avogadro will be sucked inside it and thus completing the quest.
On TranZit, the Avogadro spawns when the power is first switched on at the Power Station. Afterwards, it has the ability to appear at all major locations, except the Tunnel, throughout the map. The Avogadro will appear in a large form similar to a big ball of lightning, then appear in a humanoid shape, and fire a bolt of electricity toward where the player was standing once he transformed.
It can be defeated only with melee or one EMP Grenade, and it can only take damage when it is in humanoid form. Using the regular knife defeats it in five hits; using the Bowie Knife defeats it in four hits, and using the Galvaknuckles defeats it in two hits. The Zombie Shield also works on the Avogadro although it deals the same damage as a knife.
Upon defeat, The Avogadro will emit an eerie weak sound, spin around in a circular motion and then fly up and disappear back into the clouds. After being defeated, it will come back after a few rounds. Its appearance can be prevented by waiting for the thunderstorm to go away before killing the last zombie.
In the Proditione Fracture, Cornelius exists as a female named Cornelia. The transmission from Cornelius to Peter can be found in Revelations, however spoken by Cornelia. This radio is a variant of a similar radio from Shi No Numa.
Tower of Babble (75 / Silver Trophy ) - In TranZit, obey the voices.
- Avogadro is a reference to the Avogadro constant named after Amedeo Avogadro, which is the number of atomic particles in a single mole of sampled matter.
- Avogadro has the same health as a Denizen when latched on.
- In Theater Mode, if the player goes to free-roam and look into the generator room before power is turned on, Avogadro will be there trying to break out of the tower, but is unable to.
- Avogadro will deal a very low amount of damage in its ball form if it gets close enough, however this is very unlikely, unless its attacking in a very tight space or corner.
- Aim Assist will lock on to the generator when Avogadro is inside.