This season was overall much weaker than the last one, as we had quite many not so attractive filler episode, specially at the beginning, but this ending made it little better.
The first the main drama goes around Doug and his decision to detox a baby. His mother is happy and wants to get detoxed too. Doug not seems to believe her too much but it looks positive for the baby and mother and for Doug as the mother is not going to complain. But Weaver does. She is so sick about everything - that she runs around, does what is needed and nobody understand or cares.
The real blast comes when a man, who we see in ER in the beginning of the episode, comes back, blood every where. It comes out that he has just shot his family but there was not enough bullets. The staff troubles to save the family life and we are left in the point where they are all sent up to OR. Exciting episode, action and brilliantly done.