Campaign Story Summary (from Wikipedia):

On October 27, 2065, the Player and their teammate Jacob Hendricks of the Winslow Accord Black Ops Cyber Division are deployed to Ethiopia to rescue the Egyptian Prime Minister and other hostages from the tyrannical Nile River Coalition (NRC). However, the extraction goes awry, resulting in the Player being left behind and critically wounded by a combat robot. Rescued by fellow operative John Taylor, the Player undergoes cybernetic surgery to save their life, being installed with a direct neural interface (DNI) and receiving virtual training from Taylor and his teammates Sebastian Diaz, Sarah Hall, and Peter Maretti during the surgery, with Hendricks also volunteering to undergo surgery.

After five years of wetwork, the Player and Hendricks are placed under the command of CIA handler Rachel Kane and tasked with investigating a CIA black site in Singapore that has gone quiet. They find the area attacked by the paramilitary crime syndicate 54 Immortals and the site's data stolen, after which Kane concludes that Taylor and his team defected and murdered the staff. To learn the location of the missing data, the Player and Hendricks disguise themselves as arms dealers to meet with the 54 Immortals, but the mission goes awry when their cover is blown, causing the death of one of the Immortals' leaders, Goh Min. They manage to recover data regarding Taylor's last known location, a facility of the Coalescence Corporation in Singapore (destroyed ten years prior in a mysterious explosion that killed 300,000 people and turned most of the island's east inhospitable). The Player and Hendricks travel to the facility and discover a hidden CIA research laboratory, upon which they find Diaz leaking classified CIA information and are forced to kill him. Interfacing with Diaz's DNI, Hendricks discovers Taylor is trying to find the two survivors of the explosion: Coalescence's CEO Sebastian Krueger and Dr. Yousef Salim. After the leaked information allows the Immortals to capture Kane, the Player disobeys Kane's orders to leave her behind and rescues her by killing the Immortals' other leader, Goh Min's sister Xiulan.

The trio heads to Cairo and finds Salim, who reveals that he performed secret DNI experiments involving comforting humans via a calming exercise involving imagining a frozen forest. However, the NRC launches an invasion of the city, allowing Taylor's team to slip in and abduct Salim, after which he is interrogated and executed by Taylor. The Player, Hendricks, and Kane pursue Taylor with assistance from the Egyptian Army, but face resistance from Hall. After killing Hall, the Player connects to her DNI and encounters Corvus, a gestalt intelligence created during the experiments to monitor thoughts of DNI users, which malfunctioned, causing the explosion. Infecting Taylor and his team, Corvus made them obsessed with finding the forest, with the Player and Hendricks also becoming infected after interfacing with Hall and Diaz respectively. After finding and killing Maretti, the pair instigate a people's uprising against the NRC occupation, using the distraction to track down Taylor and subsequently corner him on a rooftop. After wounding the Player, Taylor manages to resist Corvus and tear his DNI out, sparing the Player. However, Hendricks succumbs to Corvus and kills Taylor before abandoning the Player, leaving for Zürich to find Krueger.

The Player races to Zürich with Kane to stop him. Reaching Zürich's Coalescence Corporation HQ, the pair discover Corvus has stockpiled a cache of Nova 6 gas, which it previously used in the Singapore explosion. Kane attempts to contain it, but Corvus locks her in the compound room, leaking the gas to kill her in front of a helpless Player. Continuing on, the Player finds Hendricks holding Krueger hostage. After Hendricks kills Krueger, the Player kills him in turn. The Player then tries to kill themselves to end Corvus' infection, but ends up in a simulated frozen forest created by Corvus to retain the consciousness of dead DNI users. Still alive after becoming a glitch in the forest, Taylor reunites with the Player, stating that they must purge their DNI to end Corvus. With Taylor's help, the Player resists Corvus' last-ditch manipulation and purges their DNI, erasing the virus. Stumbling out of the Zurich headquarters, the Player identifies themselves to Zürich Security Forces as "Taylor."

Taylor's mission reports reveal that the Player actually died during their cybernetics surgery due to complications. The resulting events until Taylor's death occur in a simulation deviating from Taylor's and Hendricks's experience of hunting down Dylan Stone and his team (Javier Ramirez, Alice Conrad, and Joseph Fierro) who defected after finding the CIA black site. The Player's consciousness is shown living in Taylor's mind throughout the simulation, indicating that the Player manages to take over Taylor's body after his simulated death until the DNI purge sees Corvus and the Player erased as Taylor regains control.

Overall thoughts:

I liked some of the mechanics that were also included in Infinite Warfare, like the wall running, but I didn't think the environments were sufficient to be able to use all those abilities. I played on Hardened (for most of the game), which was fun.  Near the end, I bumped down the difficulty to just be done with the campaign.  

I don't remember a lot of Black Ops and Black Ops II since it's been a while since I last played those, but it seems like Black Ops so far doesn't have much of a thread or regular cast of characters so far.  It's too bad, because I'd like to see more of the world lore unfold and get some idea of what the history of this world is.

I did peek ahead at Black Ops IV (or Black Ops IIII, if you look at the logo online), and it seems like I'll be skiping that game because it's online only, no campaign more.  Seems like a lost opportunity.

Achievements

Gameplay time: 13h 39m

Achievements: 17/98 (16 in campaign)

(o in zombies and multiplayer)

Gamerscore: 300/1950

Overall grade: B+