The keys are a one-person job, and one Lexa is just finishing. There are only a couple keys left that could fit this lock, and she nods to Cosima while reaching through the bars to try another.

"Keep an eye out down the hall and let me know if you see movement."

Finally, this key clicks the lock over and she removes the key, pocketing the key ring and looking over her shoulder at Jamie to see if he's ready to go.