Who is Isaac Morris in Agatha Cristies And Then There Were None?

Isaac Morris is person who bought Indaian Island. He was killed by Justice Wargrave when he gave him poison claiming it would help with his indigestion. He died around the same time that the ten guests arrived at Indian Island. Justice Wargrave killed him because he sold drugs to someone and the drugs caused the person's death. This made him guilty in Wargrave's eyes so he was "served justice", a.k.a death, like the nine others on the island.