The Winslow Accord Black Cyber Ops Division is a military unit of the Winslow Accord; it constitutes the "black ops" faction of Call of Duty: Black Ops III. Its story is told through the main campaign of Black Ops III (the "dream sequence") as well as through the pre-mission scrolling text logs of the Black Ops III campaign that arguably constitute the "real timeline" of the game.
The Black Cyber Ops Division's name presumably stems from the cyber augmentations that its operatives are equipped with; this includes a Direct Neural Interface as well as other surgical augmentations. Its personnel (John Taylor in the "real timeline" and "The Player" in the "dream timeline") seem to be recruited from Winslow Accord soldiers that have sustained serious injuries in combat, which consequently leads to their "non-consensual" augmentation during the course of lifesaving procedures. However, "success is not guaranteed". In the real timeline, though Taylor survives the augmentation, "The Player" does not, and subsequently dies, though they experience a vivid dream sequence before dying that distorts various missions that Taylor participated in, which constitutes the main Campaign of the game.
In the real timeline, John Taylor of the Winslow Accord is forcibly recruited into Black Cyber Ops Division after serious battlefield injuries that led to "urgent non-consensual surgical reconstruction and cybernetic augmentation" at the Zürich facility . After Taylor's successful induction into the unit, the Black Cyber Ops Division conducted an operation in an Ethiopian airfield on October 27th, 2065 with a four-man black ops team (John Taylor, Sebastian Diaz, Sarah Hall, and Peter Maretti) supported by a "secondary" contingent of Winslow Accord (the latter commanded by Jacob Hendricks and comprising a number of "new faces").
However, the operation in Ethiopia "did not go as planned", with the Winslow Accord Special Forces team becoming surrounded by NRC Grunts and wiped out with the exception of a grievously injured sole survivor. The last remaining Special Forces soldier was rushed to the Zürich facility for "emergency lifesaving procedures" and after stabilization, was considered as a candidate for the Cyber Ops program. However, the candidate died during the procedure, after being pulled off of life support.
In the vivid dream sequence, "The Player" appears to recover from the operation following the wounds, sustained during the mission in Ethiopia and begins a new career in the Black Cyber Ops Division alongside Jacob Hendricks. For the next five years, the two operatives engage in a series of missions taking them around the world; conducting actions on behalf of the Winslow Accord. Eventually, the Player and Hendricks are sent to Singapore to meet with their new CIA Liaison, Rachel Kane, after communications are lost with a CIA Blackstation. While there, the operatives find the stations' agents killed via a technique known as Denial of Reincarnation, with their eyes stabbed, ears sliced, and noses smashed in. Data drives, camera footage, reports, debriefs and everything to download are gone as well. Kane than reveals that the last team here was John Taylor's, as Hendricks and the Player reject this information.
In order to gain more information on the situation, "The Player", Hendricks and Kane attempt to recover the Black Station's stolen Data drives by infiltrating the heart of the 54 Immortals; Singapore's largest criminal element operating in the Quarantine Zone. Investigating the Coalescence Corporation facility - Ground Zero of the Singapore disaster - the operatives find out Sebastian Diaz, a member of John Taylor's team, in the lower facility levels as he has hooked himself up to the central CPU core and is trying to upload the CIA safe house and operation locations worldwide. "The Player" manages to destroy the core and wound Diaz, but unfortunately failed to secure the CIA data. Diaz dies, and the remaining 54i leader, Goh Xiulan sends 54i forces to capture Kane, who is held up at the Safehouse.
"The Player" and Hendricks escape and disobey a direct order to get to Kane and rescue her. Finding the 54i committing atrocities, the two agents make their way to Kane's location. On the way, Hendricks has doubts of Kane's loyalty, and starts to regret coming back to save her. Taylor eventually speaks to Hendricks and the Player by hacking into their comms, expressing his anger over the CIA's secret black project. Taylor asks them who the bad guys are, the yes men (CIA), or those who were left to rot (54i). In addition, Taylor express his satisfaction of seeing the 54 Immortals committing acts of brutality, seeing their anger as "righteous". Attacked by Goh Xiulan, she is subdued and killed by the Player pushing her head into flame. The Player and Kane leave the burning safe house and escape with Hendricks from Singapore.
The team then heads to Egypt to find Doctor Yousef Salim, one of the two survivors of the explosion. Dr. Salim reveals that he had worked on a secret project involving illegal DNI experiments on humans, and that his job was to comfort the emotionally unstable test subjects, using a calming exercise involving imagining a frozen forest. Taylor and his team then capture Dr. Salim, interrogate him, and then execute him. With the help of the Egyptian army, the Player, Hendricks, and Kane chase after Taylor, killing his remaining team members Hall and Maretti. The Player connects with Hall's DNI and discovers that Taylor and his team were infected by an entity called Corvus, which was inadvertently created during the secret CIA experiments that resulted in the Singapore disaster. Eventually, "The Player" and Hendricks pursue and confront Taylor in Cairo, where Taylor briefly regains his senses and tears his own DNI out of his head before being killed by Hendricks. However, Hendricks succumbs to the infection and heads for Coalescence Corporation's headquarters in Zürich with the intention of spreading Corvus to every computer in the world.
"The Player" and Kane head to Zürich to stop Hendricks, but are hampered when Hendricks hijacks the entire city's computer systems and turns its military drones on the local human defense forces. The Player and Kane manage to breach the Coalescence HQ, where it is revealed that the accident in Singapore was caused by experiments with the deadly Nova 6 gas. Corvus uses the DNI to trick the Player into believing the gas is about to be released throughout Zurich, and Kane is killed when Corvus instead vents the gas into the sealed room she is in. The Player continues on and encounters Hendricks, along with the other Coalescence survivor Sebastian Krueger. Just as Hendricks kills Krueger, the Player also kills Hendricks. In order to stop Corvus' infection, the Player tries to kill themselves, but ends up inside a simulated world created within their own DNI. There, the Player is reunited with Taylor, who agrees to help the Player fight Corvus. Taylor explains that the only way for the Player to defeat Corvus for good is to initiate a system purge in their DNI. After fighting their way through Corvus' illusory forces, the Player manages to regain control of their body and purges their DNI. As the Player stumbles out of the building, security forces arrive and ask the Player to identify themselves. The Player then responds that their name is "Taylor".
The summarization of events of the Dream Sequence, from the 54 Immortals' Uprising in Singapore to Hendricks and Kane's deaths in Zürich was created the same way the Frozen Forest was created, for the sake of allowing "The Player" to die peacefully and to have a sense of closure; inhabiting the memories of Taylor, Whilst simultaneously thinking they were his/her own.