When writing teacher Karels students start failing, he must kick it into overdrive in order to get his students to pass before the end of the Semester.

How about this:

"After a beleaguered teacher discovers his school's deep budget cuts, he has till semester's end to reach his failing but creative students before his writing program is closed."

This way you get a sense of stakes if the teacher doesn't get his students to pass. Good luck!

Nice story using Karel in your logline.

Perfect. It needs a comma in the middle though. Also Karel should have a gun.