Anticlimactic
This story begins with the statement:
The same message appears on the cover, which leads me to wonder, how exactly is Thor being enslaved a Marvel Triumph?You are about to enter the world of the future, where the mighty Thor must do the bidding of a master villain!!
Another Marvel Triumph!!
Yes, I know, typical Stan Lee hyperbole - you know damn well it refers not to the Tomorrow Man's triumph, but to the triumph of the Marvel Age of Comics, the writers (Stan) who are telling us this fantastic story... except that the story isn't all that fantastic.
Yes, Thor does have to do the bidding of the Tomorrow Man, and yes, he finds a way to beat him - but we really fall back on some of the things so common in comics (especially Superman) that Marvel was supposed to be taking us away from - such as "our hero has any power we can dream up" and "we'll throw out some pseudo-scientific sounding babble and that makes it O.K." syndromes.
When it comes down to it, Thor's method of defeating Zarrko is so contrived that it makes the victory seem hollow.
The only notable backup feature here is the Tales of Asgard story, 'Death Comes to Thor!', which is kind of a misnomer, since it is Thor who goes to Death, not the other way around. It tells the should've been more epic story of how Thor first got and used Mjolnir; but it comes across more like an interesting anecdote than thrilling comic book feature.
If you read part one, you'll want to read this second part, but if you haven't read either, you can safely skip them - they're not must-read Thor stories by any means.