Final answer:
The question is about guards and their actions, as mentioned in various passages.
Step-by-step explanation:
In the given passages, there are mentions of various terms related to guards such as sentinel, protector, guardian, and watcher. These terms are used to describe individuals or figures that stop or bar someone's progress. For example, in the first passage, a guard stops someone's progress towards a circle. In the second passage, there are mentions of guardian figures that protected the city's gates. And in the third passage, a man in an apron is referred to as a guard.