Halo 5 plot details

“After defeating the Didact, John-117 joined the crew of Infinity . . . but why did he leave?”
What’s Master Chief up to nowadays? I suspect that he’s reclining on a pile of silken cushions, surfing the Discovery channel and mashing handfuls of grapes against his visor, but Brian Reed may have a better idea. He’s the writer of the eighth Halo: Escalation comic, which explores the “secret events that immediately follow the end of Halo 4”.

Exercising my intellectual faculties just a little, I think “events that immediately follow the end of Halo 4” may be the same as “events that immediately precede the start of Halo 5”. Here’s a blurb excerpt, care of Comic Book Resources (thanks, Gameranx): “The Master Chief returns in “The Next 72 Hours: Part 1”! After defeating the Didact, John-117 joined the crew of Infinity . . . but why did he leave? The mystery begins here.” Or rather, on 23rd July, when the comic itself goes on sale.
An alleged Halo Xbox One plot summary from last August reads as follows. “In possession of a mysterious data chip, Petty Officer John-117, aka Master Chief, confronts a new battery of challenges and tests in a Herculean effort to stay alive in a galaxy where sentient life is mercilessly hunted.” It’s likely we’ll hear much, much more at E3 - here’s Aoife’s report on 343’s plans for the show.