Salem doesn't see Atlas at all, not even in passing, for almost two weeks.
It sucks, he won't even lie. He's gone all these years without Atlas and been absolutely fine, and it's not like any of their interactions have been all that pleasant! It makes no sense for Salem to care about or even notice his absence, but he does. Somehow, in this short amount of time, he's already becoming attached again.
Salem can't deny it. He misses Atlas.
He resists it with every fibre of his being. He refuses to even acknowledge it, let alone admit it to himself. Salem tries to busy himself with other things as much as he possibly can. It's not like there's anything he can do—Atlas is just respecting his wishes! No matter how miserable it makes him, he knows the distance is necessary.
So, he makes due. Kind of. Eventually, Salem gets a day off, and sadly... that's when loneliness really starts to set in.