Let's imagine, say, a professor is teaching an advanced underwater basketweaving class. And let's imagine, too, that the class grades are based primarily on a presentation, a portfolio of several baskets, and a self-evaluation of the basket portfolio. Just imagine.
Now imagine that there's a student enrolled in the class who appeared for a couple of weeks, and did the group presentation, and did a fine job at that. And then the student pretty much disappeared. But the student emailed occasionally saying that zie was coming to class the next week. And then that zie had had to miss class, but couldn't drop because [fill in excuse], and zie would do the work for the class and turn it in on the last day, because that's what the grade depends on.
How should the professor handle this?
Not that I'd be asking for a specific reason, because, of course, I don't even teach underwater basketweaving.