I'm not really sure how I feel about this whole story. It felt kind of like an underdeveloped short story idea that Morrison had and then made a book without really worrying about whether it was that good or not.
The whole thing with Mr Blue was fairly contrived - okay he's a big baddie but then also happens to be involved with running kiddie snuff porn? It felt like Morrison worked too hard to circle things back on themselves to be all "ooh cool the big mob guy and the killer santa aren't unrelated they are actually tied together guys!".
I also felt the ending was pretty weak. I get that the former partner is now going to take care of the kid but where did mom go in all of this? She left Sax and took the daughter and then I don't think we saw her again. And presumably the daughter was living with someone when she was kidnapped. Did we see or get an implication that the mother was killed? If not, we're just handing off the kid to the former partner who he had an affair with that caused the marital breakup in the first place. That seems kinda weird. And then we're supposed to get that the mob family fortune was hidden in some storefront manned by some old dude - I think that was what was happening on the last page - the partner going to get the fortune with the password. Using Google translate gives us that the italian phrase she said to the dude was "The Blue Feather" and she has a feather from Happy to present to the guy. Another case where it feels like a clever idea but not based in anything we've seen in the story before. Yeah the guy's name was Mr Blue, but it just seems very half-assed in an attempt to be clever.
I think I just talked myself into knowing how I feel about the story. And it ain't great...