I thought there was a hook_page_not_found() but I'm wrong.
I have a list of nodes that I want to end of life. They should be replaced by a 410 Gone status and common text explaining our end of life policy. In other words, I don't want to just unpublish them and let the 404 page show up.
I don't want to impose a burden on every page load, which is why I wanted to tap into page not found.
Is there a way to do this?