Yay. Constructive cruelty time.
First things first. Work on the construction of sentences. Starting every new one with a character name is pain to read, try to add some flow to the descriptions else it reads like random scraps rather than a consistent story.
Second thing. The dialogue lacks any sort of emotions. From that brief fragment i lack context of the whole story and character's involved, but it seems rather like some tense moment, yet they all act quite apathetic. There is no contrast, no conflict, they just sigh and roll their eyes while the doc apparently wants to not only go on killing spree but put them all in danger.
Another thing is general lack of dynamism. He shoots the door mechanism and yet it's described as it was a standard procedure, something that everyone would do. Just yet another uninteresting event of everyday life. It feels disconnected. It happens again later, as they leave, just like they, ah even throwing a last glance as if they had plenty of time for long, romantic goodbyes, there is no sense of danger, no pressure but plenty of nostalgia.