Question:
He hadn't paid too much attention, but the slaves seemed to be from every possible background.

Does it follow that "The slaves were all from the same country."?
Answer:
no

Question:
I quite understand that.

Does it follow that "I don't understand that at all."?
Answer:
no

Question:
I shouldn't wonder if she stole those papers from Danvers to begin with."

Does it follow that "I'm going to keep thinking about her stealing those papers."?
Answer:
no

Question:
From the Quai des Belges, you can take a cruise out to the Ceteau d'If, the island prison that was the scene of Alexandre Dumas's Count of Monte Cristo.

Does it follow that "The Count of Monte Cristo was set upon a prison island known as the Ceteau d'If."?
Answer:
yes