Uslan and Villamonte's Beowulf interpretation concludes with issue 6 (Feb/March 1976).
There are lots of abandoned plot threads, the main one being what happened to Beowulf's crew, left behind when he and Nan-Zee were kidnapped by aliens. I might even have skipped over this part, as it's not really relevant to the story, except for the magic spell that gets cast, which reads, backwards, Happy Marriage Bob and Cindy. I think this might refer to Bob Rozakis?
Anyway, the main part of the story has Beowulf and Nan-Zee in Crete, which has been abandoned, except for an old guide, who turns out to be one of Satan's helpers. Beowulf and Nan-Zee are brought to the Labyrinth, which is impressively huge.
Meanwhile, Grendel is getting all jealous as he hears Satan making Dracula his heir, and plots to get rid of them both.
So Beowulf winds up fighting and defeating the Minotaur, with some help from Nan-Zee.
And Grendel sneaks up on Satan and kills him.
Beowulf eats from the fruit of a tree in the Labyrinth that the Minotaur was guarding. Let's just say it's the Tree of Life from the Bible, because why not. The Labyrinth is really the Garden of Eden! Sure! This gives Beowulf super powers, and he now prepares to go fight Grendel to the death.
But that didn't happen, because the series ended at this point. A shame. Perhaps they could have had their climactic battle while they sailed on the Titanic, racing Hitler as he flew the Hindenberg to the opening of Disneyland.
Rarely have I read a comic that started so well, and slid downhill so quickly.
Surprisingly, this did inspire a revival of sorts not too long ago, in the comic Sword of Sorcery during the New 52. It was very different, but still called Beowulf, and more intentionally filled with anachronisms and mysteries.