Captain Marvel #17 Oct 1969
First full appearance of the new Captain Mar-Vell in "And a Child Shall Lead You!"
Trapped in the Negative Zone, Mar-Vell is told by the Supreme Intelligence that
he is trapped in this realm due to his blind quest for revenge against Yon-Rogg;
However, he offers Mar-Vell a way to potentially free himself and directs his mind towards Earth
and to the plight of young Rick Jones, who has just been rejected by his partner Captain America
Unknown to Rick, Cap has forcefully switched bodies with the Red Skull;
He follows Rick as he returns to Avengers Mansion one last time to collect his things and start hitting the road again;
When Jones gets close to an ancient Kree station which contains the Nega Bands, Mar-Vell conjures up an image of Captain America

to lure Rick Jones to the bands;

There Mar-Vell contacts Jones and explains his plight;
Given the opportunity to become a super-hero, Rick clashes the Nega Bands together and he and Mar-Vell change places.

Letter to the editor from comics historian Peter Sanderson

Script by Roy Thomas, pencils by Gil Kane, inks by Dan Adkins