Luke's in there a long time. it involves two showers, a break down and a chunk of time sitting in a corner wondering if it's too late to make a run for the water and hope something eats him.

He's feeling a lot less inclined to try and kill himself. Whatever Vader's plan, it wasn't anything immediate.

He checks outside the door for clothing and eventually comes to find Vader, dressed in his old clothes, repaired and cleaned, the right cuff rolled up past the burn to leave the stump revealed.