Loki steals the same magic ring from Odin (called “Odin Ring”) that he stole back in issue #175, and with it gets the power to force Odin into the Odinsleep. Again. Then Loki takes over Asgard.
It’s very similar to past events.
Except that Loki finally shuts Thor up. That’s cool. Then he takes his woman, forcing Sif to marry him.
Gerry Conway comes aboard mid-Loki usurpation, in issue #193 (double-sized), as Balder the Brave calls out to Silver Surfer for help, at which point is basically becomes a Surfer story.
Norrin Radd does most of the heavy lifting, beating Loki’s forces so Thor can go crash the wedding.
Lots of weddings around this time at Marvel.
It’s kind of annoying that Sif is just cheesecake here, especially since she’s had much meatier roles in other recent Thor books.
Thor gets his voice back in the end, of course.
Anyway, to punish him, Odin banishes Loki. Stupidly, he puts him on a planet where Loki can find an ally and return. Who is it that will help Loki? We don’t know yet, that’s the cliffhanger.