Interesting experiment! I'll probably read [epochwolf]'s comment after posting this and feel silly for being WAY off the mark.
First, the characters. I envisioned humans with animal traits - in this case, canine, for some reason. The medical officer I imagined as very dark and rather shaggy in appearance (despite the bony and wrinkled face, which I had difficulty envisioning since I already had the shaggy mental image in place by the time I got that far), with his facial features bunched closely together, with a weak chin and heavy brow.
Commander Ambwarra I envisioned with short white brown-spotted fur, with some sort of outfit/medallion somewhere that denotes her rank. I imagined her sitting like a human would, feet dangling on the downward slope of the hill-thingy that this is set on.
Lieutenant Kadriss...I'm not as sure. I see him more like the medical officer, lighter-complexioned, with a mischievous attitude and approach.
What it's about...I'm not sure, beyond that a war is beginning soon, and these three are a part of it. Whether or not they were on the side of those who were in charge of the slave camp is up in the air.
Funny thing is...I imagined the ship and landing zone to look almost exactly like the versions in the original Halo.
I hope that's the kind of thing you're looking for!