The Battle at the Hong Kong Sanctum was a battle that pitted the Masters of the Mystic Arts against Kaecilius and his Zealots. Having attacked the London and New York sanctums and killed the Ancient One, Kaecilius initiated the final phase of his plan to merge Earth with the Dark Dimension. His efforts were thwarted when Doctor Strange used the Eye of Agamotto to reverse time and prevent the final sanctum from being destroyed.
Kaecilius and the Zealots executed a series of attacks on the Sanctums. They invaded the London Sanctum, killing its protector, Sol Rama, in the process, before destroying the mystical facility. After attacking the New York Sanctum and killing its protector, Daniel Drumm, the Zealots fought Doctor Strange, only to be defeated by the novice sorcerer.
The Zealots then regrouped and then attempted to attack the Sanctum a second time, prompting Doctor Strange to trap them in the Mirror Dimension. However, having gained limitless power from Dormammu via their connection to the Dark Dimension, the Zealots briefly managed to overpower Karl Mordo and Strange, until they were saved by the Ancient One, who confirmed to have also been drawing power from the Dark Dimension.
Once the Ancient One revealed her true power, a fight ensued between Kaecilius and his subordinates against their former mentor. During the intense duel, Kaecilius managed to fatally wound the Ancient One, kicking her out of the Mirror Dimension before Mordo and Strange went through one of Kaecilius's portal back to the real world. The Ancient One fell from a great height and crashed to the sidewalk before being brought to Metro-General Hospital and eventually succumbed to her wounds. Before she died, she warned Strange that he would need Mordo's help to defeat Dormammu and the Zealots in the upcoming battle.
Determined to prevent Kaecilius and the Zealots from destroying the Hong Kong Sanctum, Wong ordered the Masters of the Mystic Arts to prepare for battle. Despite their best efforts, the Masters were defeated and the Sanctum was destroyed, leaving the Earth vulnerable to Dormammu.
By the time Doctor Strange and Karl Mordo arrived, they found the decimated city being consumed by the Dark Dimension. Kaecilius prepared to stab Strange with a Space Shard only for Strange to activate the Eye of Agamotto, causing time to reverse.
The Zealots freed themselves and attacked Strange and Mordo. Despite their best efforts, Kaecilius was trapped inside a tiled wall and another Zealot was trapped in a fish tank and was left to drown.
Eventually, Kaecilius freed himself and managed to tamper with the Eye of Agamotto, stopping time. Strange fled the scene and confronted Dormammu, eventually convincing him to leave Earth and take the Zealots with him.
Following Doctor Strange's bargain with Dormammu in the Dark Dimension in which the entity promised to leave Earth in exchange for his promise to end the time loop which he created, Kaecilius and the other Zealots were granted their wish as they transformed into Mindless Ones, and were sucked into the Dark Dimension. Following the battle, Karl Mordo abandoned the Masters of the Mystic Arts, assured with the notion that sorcerers abused their power and were responsible for the imbalance in the world, reminiscing that Strange would pay a price for his abuse of the Time Stone. Mordo then went on a mission stripping sorcerers of the powers, including Jonathan Pangborn. Strange returned to the Eye of Agamotto to its pedestal at Kamar-Taj, considering Wong's advice to keep it there until he was deemed ready to wear it. However, Strange was forced to wear the mystical artifact around his neck during Infinity War.
In chronological order:
- Doctor Strange
- Avengers: Infinity War Prelude (flashback)
- Agents of S.H.I.E.L.D.
- Avengers: Infinity War Prelude (mentioned)