Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: Weakest of the trilogy

'Caliban', the first in this trilogy, is a good book and well worth seeking out, so is the third one, 'Utopia'. This is easily the least of the three. Although Allen tries to expand his examination of Asimov's Three Laws of Robotics by introducing New Law robots the concept is not done with any verve, pace or excitement. As noted by another reviewer it has an Agatha Christie feel to it but without the charm or style of her mysteries. It's not even a particularly interesting puzzle. There's nothing in this middle book that can't easily be caught up with in the third. And the concept of Three Law/No Law and New Law is better examined there as well. You really don't need to spend the time on this one.