Mark is trying to make things easier for him and heal the relationship with Lewis but she is still so mad. Then he has to treat a patient who is in horrible pain and asks him to kill her. And this is a choice where noone wants to be. She is going to be dead anyway but she is on long suffering... and later.. we learn that Mark did helped her... and it will not be the only patient Mark kills.. as we later seasons see.
But some good things for him too - he gets offered an attending position but Jenn is not happy with it.
Carter and Deb - mm.. Deb is doing fine and Carter has troubles to keep up with her as he needs to impress Benton..