David Selby did a great job as the zombieized Quentin. Quentin is even spookier as a zombie than he was a ghost! Though I still find Quentin's ghost quite chilling.
I suppose Barnabas just wanted to reassure Judith, Rachel and Carl there WAS a way do deal with zombie Quentin...still he should have known Judith would want to use the cement on Quentin once he told her. He shouldn't have said that cement was the only way to deal with this mess and he should have thought of another solution for undead Quentin while waiting for him to come down the stairs if he didn't want him buried.
Frankly, I don't think Angelique really cares whether or not she changes the future, or if Barnabas does, despite her warnings. She just wants to torment him anyway she can and if that means screwing up the future, so be it. Her concerns
about what Barnabas may or may not change in the past just aren't convincing to me.
You can tell Carl wasn't up to the task of being man of the house. I would have told Judith "But you're the one who runs
the house now!" Carl's forte is playing practical jokes after all, and not much for responsibility. Loved how he shrieked when he runs into zombie Quentin.