Answer:
probably about what might happen to Huck if he dosent turn himself in.
Explanation:
it is simple no one want to be in more trouble then they are already in.
The lines "the bitter waters of captivity had worn" show how the doctor has been through many tough situations and problems, but the lines "<span>he covered up their tracks with a determination </span>" show how he does not want to show how much he actually has been throught. Hope it helped :)
