Why didn't the shapeshifter...
When she was handcuffed to the iron bar, why didn't the shapeshifter change her body to that of a little girl and pull her little arm through the handcuff? Or shift into a person who was missing an arm? Or just shift the shape of her arm to make it thin enough to pull it out of the cuff? Instead she just tugs on the cuff over and over again and almost dies from the gas. Maybe her power has limits, but it was annoying to me that she didn't at least try some kind of shapeshift to escape.
Other than that, "Deus Ex Machina" was a good episode.