Kelly was a simple Hibernian farmer who became one of the bandits in the religious cult organized by Tennyson, betraying his people. He participated in the battle of Craikennis. After the comrades around him were killed by Will's arrows, he turned and ran. Afterwards, he brought Tennyson the news of the failure.
Tennyson was not pleased. He exchanged blows on Kelly, but then apologized and presented Kelly with a necklace of immaculate beauty, who greedily seized it and hurried out of the tent.
Later, it is shown that Tennyson ordering Luciano to follow Kelly into the woods and kill him. He also asked him to retrieve the necklace, stating that Kelly stole it. Will witnessed the evil bidding and reported it back to Halt and Horace.