Issue(s): Strange Tales #126,Strange Tales #127 (Dr. Strange stories only)
Published Date: Nov-Dec 64
Title: "The domain of the dread Dormammu!" / "Duel with the dread Dormammu!"
Credits:
Stan Lee - Writer
Steve Ditko - Penciler
Steve Ditko - Inker

Review/plot: A two issue battle between Dr. Strange and Dormammu...

...resulting in Dormammu swearing to never invade Dr. Strange's realm.

This arc introduces a lot of key concepts to the Dr. Strange mythos, including Dormammu himself (who we've seen before thanks to continuity inserts, but this is his first published appearance and this is the first time Dr. Strange meets him) (Previously in this series, Dormammu was one of the mystical beings that Strange called upon when casting spells, like the Vishanti.).

It also introduces Clea...

...who mainly plays the role of a helpless captive in this story, but she does show some independence and a willingness to defy the nearly omnipotent Dormammu.

The guy in the cool purple triangular mask in this picture will eventually be turn out to be Orini, Clea's father.

This issue also introduces the Dark Dimension...

...where Dormammu and Clea live alongside the Mindless Ones.

Indeed, it is the Mindless Ones that allow Strange to win the agreement from Dormammu. When they break free of their barrier, it requires the combined might of Strange and Dormammu to contain them again. And therefore Dormammu is unhappily indebted to Strange.

When Dr. Strange returns to Earth, he finds the Ancient One jubilant. Strange is rewarded with an upgraded cloak and amulet, which i believe are the real Eye of Agamotto and Cloak of Levitation.

Strange has used a similar amulet in the past, but i guess it wasn't the real artifact.

This extra-dimensional story allows for a lot of great trippy art from Ditko...

...and has a lot of cool ideas. It's also a nice break from the seemingly constant battles with Baron Mordo.

Quality Rating: C+

Historical Significance Rating: 7 - first published Dormammu, Clea, Dark Dimension, Mindless Ones. Dr. Strange receives Eye of Agamotto and Cloak of Levitation.

Chronological Placement Considerations: This issue begins with Dr. Strange returning to his body after the events of issue #125, so Dr. Strange shouldn't appear in any other books (such as Amazing Spider-Man annual #1 or Untold Tales of Spider-Man: Strange Encounters) in between.

References: N/A

Cross-over: N/A

Continuity Implant? N

Reprinted In: Marvel Collectors' Item Classics #18,
Essential Dr. Strange vol. 1