Author Page for Two Authors

I have an author page, and I have one special case where I need two authors to write for one author page—let’s call it http://example.com/author/special-case. I realize I could either give them both access to the special-case user account or use a category page instead and instruct them select a category each time they write a post. Unfortunately, these options aren’t really feasible.

So I thought I’d try $q = new WP_Query('author_name=author1,author2') but obviously that doesn’t work. Any bright ideas (that don’t involve plugins)?