I think this story was quite well-done. As in the phone call scene in "Rosemary's Baby", so too the Mrs Carmichael on the phone scene in this story. With the title, I wasn't expecting zombies, but hey, there they were!
The parental infidelity in this story was handled MUCH better than the abusive father in "The House Beyond Your Sky" -- that's the first thing I thought of when I heard that part.
The reader's best voice was Mrs Carmichael, who sounded a hell of a lot like Rick Moranis in "Ghostbusters II".
If there was anything I didn't like, it was this:
1. Where did the zombies come from? Why?
2. The lady-or-the-tiger ending... what happens? I felt that, in this story, the fact that there was no closure -- did Dad and Aunt Sarah become zombies or didn't they? -- weakened it a bit. I kept looking at my iPod, at the time-remaining indicator, and wondering how it was going to be wrapped up.
Otherwise, a good PP. I approve.