I don’t really understand these issues.
Apparently, Sif was captured by the aliens from the last story, but I thought she was on Earth and not in Asgard.
So, they go retrieve her. By the time it’s all over, Thor and Sif are riding through space on a Viking spaceship together.
Creators: Gerry Conway, Sal Buscema (#214) and John Buscema (#215-216)