Everyone knew, of course, how much Peter meant to Walter, and so it was obvious how much Peter's disappearance was tearing him apart. He was even more jittery than usual, struggling to put two words together, let alone a sentence. One more than once occasion over the following few days, Astrid would arrive at the lab, or come back from the bathroom, to find he'd tucked himself in a corner while silent tears streamed down his face.
Agent Dunham's feelings about Peter were a little less obvious, but Astrid had been working with Fringe Division a long time now and could read the signs. There were moments where Olivia would turn around and open her mouth as though to ask a question or address someone, only to turn back, her shoulders slumped slightly. Other times, Astrid would be in the car with her (instead of Peter) and could see how Olivia gripped the steering wheel tightly and stared straight ahead; if Peter had been there, some kind of conversation or another would have been flowing.
Astrid missed him, too, of course. She missed his sarcasm, his and Walter's moments of father-son bonding, his offers to drive her home at the end of a long day. But in Peter's absence, someone had to hold the team together and it didn't look like it would be either of the other two any time soon. So it'd have to be her. She'd give Walter the hugs and the shoulder to cry on that he needed, and try to draw Olivia back out of that shell she was so good at hiding in. And as for who would look after Astrid? Well, she'd worry about that later.