Reed Richards figures out how to give Banner the power to choose to turn into the Hulk. But before that, Thing and Hulk fight again.
I’d say this is an important episode in the evolution of the Hulk, but his ability to control the transformation seems to always come and go. In fact, he already got this ability once before, in Tales to Astonish #70. And he loses the ability in the very next issue.
Also, Banner proposes to Betty Ross.
Creators: Roy Thomas, Herbe Trimpe