It was too damn quiet, but there wasn't anything they could do about it. Making any noise, any form of disturbance would likely ruin the entire mission.
There were too many Watchers lying dormant around the city. It would all be ruined even if a single one of them woke up and stirred up the hive. The Infestation would tear the entire city apart, brick by brick, to find the disturbance...
And they'd probably lose their only guaranteed chance to acquire the sample they needed.
What Reed and Lu'um were seeking was a genetic sample of the Emperor.
Reed already had the necessary materials to bring the dead back to life, even if they were only clones. With his taboo mastery of the flesh and the soul, he had actually cheated Death more thoroughly than even the Ancient Mulians had accomplished.