Derek was woken up by the pain in his back.

He leaned against the bathtub in this position, so when he slept, his arm quickly became dislocated.

Last night he helped Bertha and forgot to apply medicine to him. He was also careless and bumped into the sharp edge of the bed. He guessed that his back was more swollen than before.

He sighed and tried to sit up when he suddenly discovered that Bertha was not in the bathtub.

What did she wake up for?

He didn't know anything, it seemed that ...