Kromp aimlessly wanders the halls of the manor, exploring the rooms that are large enough to hold him comfortably, while checking for potential threats. That's one of the things you're supposed to do as a bodyguard, but he isn't quite sure what a 'potential threat' would look like on this planet. He eventually concludes that, if he doesn't find anything in here that's weirder than what he's seen outside, it should probably be fine.
Kromp had never seen so many xenos in one place...at least, not so many different kinds. He had always been taught that the Emperor hates xenos, so he should hate them too. But it's easy to hate a xeno that's trying to kill you while calling you a "mon-keigh" or screaming "WAAAGH". These ones seem...different. Do they really deserve to be wiped out?
Eventually he comes across the master bedroom, where he finds Matthias fast asleep in a soft-looking chair, with an open book in his lap. Kromp had never understood how reading worked. He learned how to sound out the letters on a page, but apparently you're supposed do it in your head somehow. Then the letters are supposed to tell you stuff that you didn't already know, but he'd never figured out how to make that happen. He'd long accepted that it was just one of those things other people could do that he couldn't. But whatever Matthias had been reading seemed to have tired him out as much as any reading tired Kromp out. What kind of book could be too much for the brilliant Rogue Trader to handle?!
Then Kromp remembers the look on Matthias's face just after they came into the manor. He still had his usual smile, only it had started...sagging. Like holding it up was taking a lot of effort. Matthias had once told him about the concept of pretending to have feelings that you weren't actually feeling - another one of those things Kromp had never figured out how to do. Still, no wonder Matthias had fallen asleep, with combined the effort of using that pretend smile and reading that tricky book!
Making sure not to wake his master, he grabs a sheet from the nearby bed, drapes it over Matthias as gently as he can, helps himself to a quick swig of amasec, and leaves the room with all the stealth he can muster.