Y’ever think about how Alpha-Nine fell apart because of the Rookie’s death? I think about that a lot.
The Rookie went out in a jarring way. He lived to see the end of the war against the Covenant, lived to see all that. And then he was taken hostage by insurrectionists and shot in the head.
We were shown that there was almost as immediate impact on the team, but it didn’t fully surface until the Rookie’s funeral. Dutch reveals he’s retiring, Romeo and Mickey get into a fight because Romeo blames Mickey on the Rookie’s death, and Buck has to resolve things. We don’t see a lot more from there, as it then goes on to focus on the Spartan training that Buck, Romeo, and Mickey eventually go through.
However, we know that at some point, Mickey became involved with the rebels. Some messed up versions of survivor’s guilt caused this, and while on a mission with Romeo and Buck, he revealed his true colors. He ultimately was captured and presumably punished for his crimes, but it’s interesting to see how the team all fell apart because of Rookie’s death. It’s what caused Dutch to retire. It’s what caused Mickey to become a traitor. It’s what caused Buck to eventually move away from Romeo and join up with Master Chief and whoever else is there.
One thing caused everything to come crashing down, and all it took was a bullet.