Great Expectations Questions

At first the book was hard to understand, yet after getting used to the language and how the characters talk the Great Expectations became very interesting and intriguing. What I am not quite understanding however is at the end of the third chapter (pg. 19) when the 1st convict says "Where is he?...I'll hunt him down like a blood hound." The convict is referencing the man Pip said he had seen in the marshes before giving him the food. Why is this man scared of there being another convict in the swamp? Please help! Thanks!

Group essay

Dear group, 

Reviewing over my body paragraph I realized there were a few changes that needed to be made. First I read through for any grammatical errors and fixed those, but the primary thing I change was adding different synonyms for words I though I was overusing. All of my Concrete details and Commentary remained the same ideas. What I am having the most difficulty with is 1. creating different ways to say "the imaginary person one character created of the other" 2. While introducing each quote, expressing who is saying the quote in  another way than saying "Jack said to Algernon" or "Gwendolen said to Jack" for examples and 3. other synonyms for couple and relationship: I have come up with pair and duo so far. The last thing I am having difficulty starting is the transition sentence from Leah's paragraph to mine. Any main theme I should keep in mind, or anything major I should definitely include when writing this sentence? Thanks in advance for your help!