@aprilisthecruelestmonth for Day 26 and the themes "Beaten" and "Failed Escape", I want to recommend "Sanatorium" by ApplesOfAvalon! (and their "I'm dead and Upstanding Yuck killed me" series in general, but especially Sanatorium.)

A darker take on "Upstanding Yuck" and Yuck's little... "rehabilitation". I love Yuck as a character and the way he's explored in these fics! Big heads up for torture, being held captive, mind breaking and abuse in this one.