This issue came out a while ago.
The story pertains to when during One Million BC, a force of gods and cosmic entities chased down a rogue Celestial. Among the force was:
Starbrand (apparently using a troglodyte as a host)
Phoenix (also using a troglodyte host)
Ghost Rider (three trogs?)
Kind of a lame parody of the Avengers, but a heavy-hitting force. Odin said that he had injured the Celestial with the Odin-Force, and the Phoenix mentioned something about striking with enough power to melt a supernova.
I assume there is supposed to be some connection to the events which culminated with THOR #300, even though the timeline is messy (2000 years compared to 1,000,000 years). Blame it on the Eye of Odin.
The Celestial they had apparently defeated awakens in the present time and alludes to the 'Final Host'. I guess this is a post-Mangog storyline to come.