Premise:
"At the top end of the lake, you wander into dense forest through a fantastic chaos of rocks and grottos that according to local tradition are variously inhabited by the Devil and King Arthur himself."
Hypothesis: King Arthur and the Devil are happily married and make their home in the dense forest.

it is not possible to tell

Premise:
", curves, crowded lanes, etc."
Hypothesis: winding, busy lanes

yes

Premise:
"Slate when I was hustled over to that no-work job at the Pentagon."
Hypothesis: Slate when I was moved over to a no-work job in the Pentagon.
yes