Nice chapter, I like the way you portrayed Sarah Jane's reactions here—most of all her fierce, rageful passion, and her being ever so aware that she was only alive because she was amusing and distracting the Master, and that she had to keep doing that if she wanted to live. I also liked her waking up alone, and how puzzled and panicked she felt, not knowing at all if he would return. It was also very interesting how the whole thing accidentally brought a closure of sorts to her relationship with the Doctor, or at least the part of it that had still been nagging at her. And I just loved the parts about the Brig, and her imagining his lecture and thinking he sounded so normal and safe ♥ The ending made me crack up too! ;P

A few things I picked up on:
"It was harsher, crueller; this time around": no need for the semi-colon, no?
"as is she was a new and interesting toy.": if
"would she lay in a sorry heap with a broken neck now": lie
"not by the person man she had just spoken to": person or man ;)
"her hair and makeup was immaculate": were
"Sarah Jane, feeling self-conscious straightened the collar of her blouse knowing it hid the marks the Master’s fingers had put on her throat.": another comma after "self-conscious", plus one before "knowing"?