While defending the New York Sanctum from the Zealots, Stephen Strange used the Rotunda of Gateways to trap his right-hand man Lucian Aster in a rainforest. After trapping and restraining the separatist faction's leader Kaecilius, Strange learned about the Zealot's plan to merge the Earth with the Dark Dimension as well as the Ancient One's attempts to prolong her life by drawing power from the Dark Dimension.
Unbeknownst to Strange, Lucian managed to find his way back to the Sanctum and crept up behind the distracted sorcerer. Just as Strange noticed that his Sling Ring was missing, Lucian stabbed him with a Space Shard. The two engaged in hand-to-hand combat only for Lucian to gain the upper hand.
At the last minute, the Cloak of Levitation wrapped itself around Lucian's face and proceeded to suffocate him, allowing Strange to find his Sling Ring and conjure a portal leading to Metro-General Hospital.
Seeking out Christine Palmer, an old colleague, Doctor Strange convinced her to operate on him despite her confusion towards his random presence. She brought him to an operating room and began to treat Strange's wound only to be surprised when Strange projected his astral form to assist her.
Meanwhile, Lucian Aster managed to escape from the Cloak of Levitation by projecting his astral form and followed Strange through the portal to Metro-General Hospital. Detecting Aster's presence, Strange engaged the Zealot in a fierce duel that took them throughout the hospital. When Strange's heart stopped beating, Palmer used a defibrillator to shock his body, causing his astral form to release an extremely powerful shockwave that caused Aster to cry out in agony. Realizing that the shock from the defibrillator increased his power, Strange told Christine to increase the voltage on the defibrillator.
Despite her protests that Strange's heart was still beating, Palmer did as she was told and shocked Strange's body again. As a result, Strange's astral form released a far more powerful shock wave that incinerated Aster's astral form while simultaneously causing his physical form to stop operating.
- "Where are you going?"
"Just tell me the truth?"
"Well, a powerful sorcerer, who gave himself over to an ancient entity who can bend the very laws of physics, tried very hard to kill me. But I left him chained up in Greenwich Village, and the quickest way back there is through a dimensional gateway that I opened up in the mop closet."
"Okay. Don't tell me. Fine."
- ―Christine Palmer and Doctor Strange[src]
Doctor Strange's astral form returned to his body, allowing Christine Palmer to properly tend to his wounds. After apologizing to Palmer for his rude behavior and telling her about his time at Kamar-Taj, he returned to the New York Sanctum, where he found the Cloak of Levitation still wrapped around Lucian Aster's corpse.
Strange allowed the Cloak to rest on his shoulders before discovering that Kaecilius had managed to break free from the bands. He then ran into Karl Mordo and the Ancient One, who were both surprised to learn the Cloak had chosen Strange.
After being briefed about Kaecilius' abilities, the Ancient One noted that the New York and Hong Kong sanctums were the only thing preventing Kaecilius from carrying out his master plan. She went on to note that, since Daniel Drumm was now dead, the Sanctum needed a new protector and nominated Strange as Drumm's replacement.
Strange, however, refused the offer, arguing that his role in Aster's death went against the oath he took to save lives and not end them. When the Ancient One claimed that he was still set on feeding his ego, he shot back by alluding to her drawing power from the Dark Dimension.
Although Karl Mordo outright denied the accusation, the Ancient One did not and warned Strange to choose his next words carefully before leaving the Sanctum. The moment she did so, however, Kaecilius and the surviving Zealots launched a second attack on the Sanctum.