So, not too long after Kate left a voicemail for Bobby, he was leaving one for her:

"This might not matter since you might still be gone by the time I get back, but if you do get back and I'm not around... stuff came up for me too. Guess it's just one of those weeks, huh? Anyway, stay safe, with whatever's going on with you, and I'll see you... later. Whenever. Bye."