You already have the first, but the second was released recently on Steam. I don't think it's available anywhere DRM-free yet, but seeing as how you have the first one I think it's hopeful that they'd be willing to release the second one here.
Steam page: https://store.steampowered.com/app/1259840/The_House_of_Da_Vinci_2/
I hope you do get it, because I'll only buy it from a DRM-free store and I'll buy it from the first place to get it.