Excuse the vagueness I'm trying to keep this spoiler free as possible!
This season has had it's ups and downs trying to negotiate the aftermath of season 3, even seemed to loose its way at times with a few of the story lines getting turned on their heads. There is a certain character who upon arriving at Mars starts to set the record straight and proves their brilliant mind has not been idle. Their expert negotiation skills and ultimate aim for being up there are only revealed in the final few scenes of the episode.
However it's only when they visit Ed and we think the conversation is going to go one way, it turns a complete 180, like Mad Max busting a J in supercharged Interceptor. That final line and the look on Ed's face just sealed the insane direction this show is about to take.
I imagine if they ever did more prequel novellas for The Expanse this new story arc would have slotted in perfectly, it's one hell of a twist! Fingers crossed they pull it off!