The lead story is reprinted from THOR #130 (1966) and is a big action issue, with Thor facing off against the hordes of the underworld to save Hercules.
It's a great ever-escalating battle, which finally threatens to bring down all that Pluto had built, bringing him to return to stop the destruction. There's a fun bit of contrast between Hercules love of battle and Thor's dedication to justice in the end.
Meanwhile, in Midgard, the story of Tana Nile starts to develop with more clues about her secret, as she sends Jane Foster away in order to lure Thor into a search for her.
The back-up is a Tales of Asgard story from JOURNEY INTO MYSTERY #118 (1965), "The Crimson Hand", continuing the major quest storyline. In this story we see Thor preparing for the voyage, being given the Crimson Hand, which can be used to force anyone clasping it to tell the truth. This comes in useful when Loki brings by a volunteer for the quest, who turns out to be an assassin planning to kill Thor. Loki manages to avoid detection of his own role in that, of course. They sure did give him a lot of leeway back then.
Colletta inks throughout, of course.