I'm stoked to hear it! Crow's turned out a lot more interesting than I was expecting, since I initially planned for him to just go back to his old life, but then realized that wouldn't be realistic for his character after the influences Penelope had on him ^^
I actually had a different plan for the way Albin reaches out for him, but I think we could fit John into it pretty easily. Basically, during part of his travels, Crow ends up back with Evelyn and Hazel for a while. While he's there, Evelyn tells him that a royal messenger stopped by with a letter for him from the king, who he also learns is his father at this moment. Since he stays under the knights' radar so well, the messenger just left the letter with a tavern keeper in Silverpool (the knights did know he traveled through there occasionally, even if they didn't know when) in the hopes that she would run into him at some point and give it to him.
Still wanting nothing to do with Albin, Crow doesn't bother having her read it to him (I mentioned very subtly earlier in the story, but Evelyn is one of the few, self-taught literate peasants in the outer villages). Instead, he just holds onto it for months because he also can't bring himself to destroy it out of his own morbid curiosity. So, he actually doesn't respond to Albin's invitation for a really long time.
This is where I could see John coming in:
After going for so long with no response, Albin starts to consider options about what to do with Crow, because he can't leave him causing trouble on the streets just because he didn't answer the letter. I could see him thinking about assigning some of the knights on the battlefront to just "take care" of him, though he would be hesitant for two reasons. One: because he doesn't want word to get out about his relationship to Crow to anyone; and two: because he needs a new ambassador after Abraxas died, and he hadn't been able to find anyone else with the skill set to fill the position. He would end up confiding in John, since he already knows about the scandal, and end up realizing he could just send John to the outer villages to deal with his son. Albin would end up sending John to find out why Crow wasn't responding to his invitation in the first place and gives him last resort instructions to kill him if he continues to refuse.
Also, I'll get a post up as soon as I get back from my run this morning ^^