Tales To Astonish (1959) #70, "The Start Of The Quest"

Looking back at Defenders reunions has been fun but most of them have been fairly recent. Let's go back in back in time a bit and to stories more specific to the avenging star of this show.

His own series!!!  Which he...shares with the incredible Hulk!

Well, it was still a promotion of sorts. Namor had returned to some prominence in 1962 after being off the radar for about seven years. He showed up in the various team books at the time; Fantastic Four, Avengers, X-Men...He appeared in Daredevil in April 1965 (cover date, natch) and even though it was published four months later (August 1965, obviously), Tales To Astonish #70 takes place immediately after that guest-spot. 

In that Daredevil issue, Lady Dorma tracked down Namor to let him know that one of his warlords, Krang, had planned a coup to take over Atlantis. When Namor reaches Atlantis, Dorma confirms that Krang was successful but because he rejects her advances, she rats him out.

Yet he is ultimately captured and tossed in the dungeons by Krang. When Dorma comes by to visit because "her heart would not permit her to stay away", the imprisoned prince reminds her that there is one way to reclaim the throne even if his people have accepted Krang as their leader.

Wow, Neptune really saw this coming!

Dorma helps Namor escape so that he can begin his search for the trident.

Off he goes to the Cave of Shadows, the location of the first clue in his quest.

But Krang ain't no sucker! He totally anticipated Dorma's actions and let them come to pass thinking that Namor is just going to get himself killed anyway.

At the Cave Of Shadows, Namor promptly finds the clue in a red sea shell. But it is guarded by giant-ass squid!

He finds that the exit from the cave is blocked, blames Krang (irrationally, really, but apparently accurate) and we end on that note.

The story was by Stan Lee and the art was by Adam Austin. The story of the quest would run through issue #76.