At Derby Day, Tommy sets his plans in motion, though not without casualties. Polly winds up confronting Major Campbell with brutal results.
Arthur gets a bad surprise when he visits Alfie Solomons. And when Michael lands in jail, something worse happens to his mother.
Tommy gets to know May Carleton a bit better. Meanwhile, things with Campbell and the IRA get very complicated and dangerous for Mr. Shelby.
Polly's long lost son Michael becomes a part of the family. Maybe a bit too much for her liking.
Tommy manages to keep himself alive. He gets back to London to speak with Alfie Solomons, and later writes a letter to Winston Churchill himself.
The day's come for Tommy and the Blinders to oust Billy Kimber. But Grace, Campbell, even Ada, they put a wrench in those plans.
Grace and Tommy get closer than they should, as Inspector Campbell gets jealous. Meanwhile, Arthur Sr turns up again causing a bigger rift between the brothers.