"The Crypts of Kaa-U!"
Alone on the dead husk of Kathulos, Doctor Strange has to come to terms with dying without notice or recognition, or somehow finding a way back to his own dimension in time and space.
Strange employs utter ruthlessness to destroy Kathulos from its very core, hoping to draw Shuma-Gorath into the open. The ploy succeeds. Shuma-Gorath speaks to Strange in the disembodied void, tantalising the magician with hints that the Ancient One may have answers on the Dread One's origins.
The all-seeing light of the Eye of Agamotto divines a path back to Earth's dimension. All the way in fact, to the crypts of Kaa-U, where the venerable Ancient One is held captive.
The magician finds his mentor in a frail condition, and can't quite understand why the Ancient One is reticent to be emancipated from the Shadowmen of Kaa-U.
When the wizened mystic intervenes to save Doctor Strange from overwhelming numbers of Shadowmen, his complete power expended, and with his dying breath, a disembodied voice is heard once again. Shuma-Gorath's secret is revealed - the Dread One has awoken from his sleep, buried deep in the mind of the Ancient One.