I thought this was a good, solid episode. Dr. Finn is a great character, and Jerald is extremely entertainig.
My only complaint would be that I thought that Finn would have/should have shared more intelligence with Isaac when she made contact. I expected her to inform Isaac what she had been told about the contaminant in the water after learning that her son was sick and that Isaac and the children might encounter her captor while he was attempting to recover gear from the wreckage.
I was reminded of 10 Cloverfield Lane, but fortunately they didn't push any parallel with it too much.
This week I'm voting excellent.
10 Cloverfield Lane came to mind too.