Series 2 · 1922Edit
Alongside Finn Shelby, he witnesses Arthur Shelby Jr. kill a young boy during a fight, but when Thomas asks the two the details of what happened, Isaiah refuses to speak, because he is not a member of the Shelby Family. Instead, Finn tells Thomas what happened.
Isaiah is a friend of Michael Gray, and convinces him to get drinks at The Marquis of Lorne. There, Isaiah and Michael get in a fight with a man who refuses to drink in the same bar with Isaiah and refers to him as a "nigger".
Series 3 · 1924Edit
Isaiah is a close friend of Michael Gray, son of Polly Gray, and introduces him to the ins and outs of being a Peaky Blinder (such as drinking and smoking) when Michael first joined.