Back in the days when comic book series routinely added a king-size stand-alone issue once per year, the Defenders had only one "annual" of their own.
Published in 1976, Defenders Annual #1 opened with the team watching a videotape of agent Jack Norriss describing uncharacteristic emotional reactions on the part of the heroes ever since their encounter with the Headmen in Defenders #33.
That call to action prompted Dr. Strange, Valkyrie, Nighthawk, Red Guardian, and Power Man to investigate a series of unusual political turnabouts across the globe. With help from the Hulk, they thwarted the Headmen's bid for world domination in the process.
But the Headmen weren't the only threat at hand.
Having surmised that Nebulon might be responsible for some of the international upheaval, Dr. Strange held his ground against the extraterrestrial instigator during a climactic battle of wits. While Nebulon told of his plans to mentally reprogram humanity into a state of "liberation," the sorcerer maintained that "free will" was a necessity for the people of Earth.
- Dr. Strange: We attain our most glorious heights when we admit our ignorance … and force onward to surmount it. Perhaps this classes us as anomalies in the universe, but--
- Nebulon: Enough, Strange! I concede! Your race is beyond redemption! And so I hereby abandon my efforts--to--
Although Nebulon disappeared at the end of the debate, he became one of the Defenders' most persistent foes.