In the latest trailer for Halo: Nightfall, the miniseries packaged with The Master Chief Collection to bridge the gap between Halo 4 and 5, there’s a few important things to take note of. Some of them could have major implications for the next year’s Halo game.

1. “One man that was a Spartan.”

In the trailer, we meet ex-Spartan Colonel Randall Aiken. If you’re a super Halo fan, his name might sound familiar. That’s because there was a Spartan named Randall first mentioned in the book Halo: Ghosts of Onyx. Currently, he’s one of the few Spartan’s listed as missing in action by the super soldier creator Dr. Catherine Halsey.

Randall-037 was a Spartan-II who went missing in the year 2532. For reference: Halo: Reach, the first Halo game chronologically, takes place in 2552. Halo 4 takes place in 2557, which would make Randall Aiken in Nightfall look about the right age. If he survives Nightfall, we could see him make an appearance in Halo 5: Guardians.

2. Was that the flood?

The crew of Halo: Nightfall will eventually find a fragment of the Halo the Master Chief blew up in the first game. No doubt there’s still some nasty Flood still hanging out in the deep recesses of the broken ring world. The hand in the shot that grabs Talitha Macer definitely looks decayed and human like a Flood’s would be.

The trailer doesn’t tell us much but it does hint that the Flood could return to the Halo games, after not appearing in Halo 4, if they’re not taken care of in the show.  Earlier this year it was hinted that they would return in the comic series Escalation.

Are you read to fight the Flood again?

3. Okay, tin foil hats. Here’s some theories.

One thing to keep in mind is that, in the games, we’ve not seen the most dangerous Flood forms. When the past civilizations like the Forerunners fought them, they were much more dangerous.

Some Halo fans believe that the figure that splits into what looks like hundreds of little creatures is an advanced Flood form we’ve never seen before. We know that the Flood can be intelligent like the Hivemind we see in Halo 2. Could the Flood return in an even more dangerous form?

Some people are crossing their fingers in hopes that the creature is actually a Precursor, Halo’s primordial beings that are even more mysterious than the Forerunners. Maybe it’s a surviving element of the Precursors? Or something worse? The theory doesn’t make a lot of sense yet because there’s little reason for a Precursor to be on a fragment of Halo, but we can at least speculate.

These are all things to keep in mind when checking out the series when it launches on Nov. 11.