I'd like write a wordpress plugin for Wordpress to deal with missing publish much like how wiki made it happen.

Say I've got a released publish known as abc1 along with a draft publish abc2. I've my link configure as domain.com/abc1 for that released publish. Now when user access domain.com/abc2, I must show a custom page (like 404). But i'd rather not redirect, therefore the user can continue to bookmark the hyperlink and return later when abc2 is released. But when the publish never been around (not released and never within the draft), it should redirect towards the usual 404.

How must i handle the "missing link" with this situation?