Text: But on a second hail from the rooftop sentry post Rennie swung the rifle over his arm and faced the outer gate of the patio.
Entailment: Rennie swung the rifle over his arm and faced the outer gate of the patio on a second hall from the rooftop sentry post.
Contradiction: But, on a third hall from the rooftop sentry post Rennie was playing with the gun in his hand.