Actually the Hulk never really went away. Although his own comic was cancelled, the Hulk popped up in the first couple issues of the Avengers and in Amazing Spiderman #14. Then, in Tales to Astonish #59, Giant Man decides to try to find the Hulk and get him to rejoin the Avengers. Unfortunately, the Hulk mistakes his interest for a threat and so they have a battle before General Ross, believing the Hulk to be alone due to a trick by the evil Human Top, fires an atomic shell at them. Fortunately the Hulk catches the shell and hurls it to where the Top is hiding.
About 3/4 of the way through this story, Marvel announces that effective with the very next issue, the Hulk will be taking over the backup spot in Tales to Astonish.
Steve Ditko, who'd stepped into Jack Kirby's role as artist and plotter with The Incredible Hulk #6, resumed those chores in TTA #60. In the first story back, Bruce Banner realizes that it is stress which turns him into the Hulk. Unfortunately, he cannot avoid stress because of his work for the military.
He has been designing a powerful robot that is virtually indestructible. Unfortunately a spy steals it and only the Hulk can hope to defeat it. During the heat of battle, the Hulk's emotions overload with anger and he converts back to Banner (getting away before the spy in the robot can see him).
TTA #61 continues the story. Major Glenn Talbot arrives at the base; he will be Banner's chief rival for Betty Ross' attentions for years. Talbot is convinced that Banner is a spy, and he enlists Betty to try to help him find Bruce, who is out in the desert looking for the robot with an electronic scanner.
Talbot shows himself to be a hero when the robot tries to kill them with a boulder, pushing Betty out of the way while risking his own life (fortunately the Hulk saves them both). She sees the major in a new way. Meanwhile the Hulk is battling the robot. He knocks the robot into a bottomless pit, then saves the base from a rocket the spy had sent its way. However, the blast from the rocket leaves him kayoed, and helpless as Talbot and Ross bind him up in an outfit ironically designed by Bruce Banner himself.
The third part of the story is in TTA #62. The Chameleon, last seen in Amazing Spiderman #1, comes to the army base, working for a mysterious figure called The Leader. He impersonates both Ross and Banner, escaping with a Gamma-Ray bomb and Betty. But the Hulk chases him down and in fear for his life, the Chameleon tries throwing the bomb at the Green Giant. Of course, it just turns him back into Banner.
Comments: One of the obvious flaws in the series is that Banner is constantly being found out in the desert, with raggedy, torn purple pants. What, nobody notices those are the same pants the Hulk was wearing?
Prior Entries on the Hulk:
Incredible Hulk 1-3
Incredible Hulk 4-6