There's so many possibilities for a Strike/Johnny meeting. At the moment I'm leaning towards either Johnny rocking up at the office & talking to Robin because Strike's out, or there being a letter that Pat opens thinking it's agency business & she tells Robin about it because she doesn't know how to broach the subject with Strike. I'm fairly sure that Robin will be instrumental in any reconciliation.
There's always the possibility that Strike will just outright refuse to meet him & regret it after he's gone. Maybe there might be a letter or a share of the inheritance & we'll see Robin having to help him deal with it. Or perhaps there'll be a deathbed moment like he had with Joan & he can reflect on the differences between the two experiences.
I really hope that Johnny really does try to apologise in a genuine way, not a protecting/enhancing his image way like Strike assumes. I'd love to have him tell Strike that he'd let Leda's behaviour colour their relationship & the drugs hadn't helped but that he regretted it. I want him to acknowledge that he's behaved badly & he can't change that but he wants to change things going forward. I do think, though, that that might be quite hard for Strike to hear. At the moment, he can hate his father & blame him, at least in part, for his upbringing. I get the feeling that he knows the Leda was rather chaotic but, like Charlotte, he sees her as a victim of her past, or maybe of her mental health, but a victim nonetheless. To accept that Johnny isn't just an awful person he'd have to accept that Leda was responsible for souring their relationship. Had Leda not repeatedly chosen to blow all the child support & demand more money perhaps Johnny would've been more inclined to have a more amicable relationship with Strike. I'm not suggesting they'd have been besties & Johnny would've been getting father-of-the-year awards, but maybe it would've been different.
I think it's quite telling that Lucy has a lot of anger towards Leda. She doesn't see her as a victim but as a woman who made bad choices that were detrimental to her children. Am I right in remembering that Lucy's dad was a bit more of a stable presence in her life? Strike could've internalised that as it being solely Johnny's fault because Lucy's dad managed to maintain civility with Leda, therefore the problem couldn't have been her.
I may be slightly overthinking all this... 