Kieran Duffy

Kieran is described by Arthur as a "gentle buffoon". This is shown best during "Old Friends", as he is being chased by Arthur, he doesn't open fire on him despite this, and upon falling off his horse, he still doesn't, and simply surrenders, saying "Don't hurt me, please!".

Duffy is soft-spoken and nervous, often stuttering when he speaks. He stutters a lot especially when speaking with Arthur, and although he has a crush on Mary Beth and seems to have no trouble speaking to her or complimenting her, he becomes shy and stutters when she returns his advances. He generally has a kind-hearted demeanor and avoids conflict when he can, as when he agrees to drink with Bill Williamson even after being physically threatened by him so often.

Although the gang kidnapped him, he seems intent on earning their trust and becoming a fully-fledged member. He tells Arthur that he plans on proving himself to him. When Jack is kidnapped, he tells Abigail that he would give his life for Jack if he could. He becomes genuinely frustrated whenever someone refers to him as an "O'Driscoll", and zealously told Dutch upon meeting him that he hates Colm O'Driscoll.

Kieran prides himself to be a good fisherman, up to the point that he tries to bond with Arthur and gain his trust by going fishing with him; he reveals that fishing is one of the very few things he had the time to learn from his father, along with taking care of horses, another activity he shows to be fond of.