When "The Sensational NEW" Captain Marvel ended its five-issue run in late 1970 with issue #21, you can't say they didn't send him out with a bang:
Issue #17, which began the adventures of Mar-vell in his new costume, continued the title's publication schedule without missing a beat, which made it seem to the buyer that Captain Marvel was simply continuing the original series while taking the character in a new direction. But it would only take three more issues before it became apparent that the book was on life support. Its fourth issue, #20, was delayed for a whopping six months, with its cover doing its best to make lemonade out of a lemon:
Another two months would pass before the fifth and, as it turned out, final issue went on sale. Though to hear Marvel tell it, these five issues of Captain Marvel were never meant to be more than a limited run:
Oh, I'm guessing your readers had already rendered their verdict, gentlemen.
Yet, putting aside the spin, I must say that the creative team of writer Roy Thomas, artists Gil Kane and Dan Adkins spared no effort to close this series with a decent issue, featuring a fine matchup between Mar-vell and the Hulk and showcasing each of them nicely. I don't know what kind of an audience its story found at this point, but in hindsight you have to wonder what was fundamentally missing in this character that such talents as Thomas, Kane, and Adkins couldn't pull him out of his nose dive and make the book a top seller. If the character of Captain Marvel was ever going to find his legs, it should have been here, and with these people holding the creative reins.
The story actually begins in the prior issue, where Rick Jones has sought out Bruce Banner at his hidden lab in the desert, in the hope that his old friend can free him of his dual existence with Mar-vell:
Naturally, the closing pages of that issue use a raging Hulk on the verge of attacking Rick to prod readers into picking up the next issue. Which probably gives you an idea of what's wrong with this title: can't Mar-vell close his own issue? Isn't he enough of a draw to sell the next issue of his own mag?
In fact, the Hulk is handled so well in the follow-up scene, you're almost wondering who's supposed to be carrying this story:
With the situation defused, the Hulk changes back, and Banner gets to work on finding access to the Negative Zone. Here, as in a later Avengers story, Thomas finds a reason not to seek assistance directly from Reed Richards, who can basically say "sure, no problem, glad to help" and have Mar-vell out of the Negative Zone before you can say "Annihilus," so we have to swallow that Banner can throw together something from scratch to access the Zone. At least the story provides a further complication, when a colleague that Banner wishes to consult with at a nearby university ("Desert State University"--what else?) is being besieged by student protests, which puts additional strain on an already strained Bruce Banner:
The Hulk, in his rage, lashes out and destroys all the lab equipment that Banner had finished up to that point, dooming the project. And when Rick changes to Mar-vell, who attempts to calm the Hulk--well, Mar-vell isn't going to rack up any sales that way, is he?