Season 6 of Peaky Blinders begins with a breakdown of Season 5's heady moments, as well as answers to who prevented Mosley's murder and why.
The finale of Peaky Blinders season 5 left both fans (and Tommy himself) wondering why his seemingly murderous plot went awry.
However, it turned out that the failure was even worse than previously thought. That's how the IRA found out about the murder and whether or not Moseley knew about it.
Tommy's plot to assassinate British Fascist Union leader Sir Oswald Mosley (Sam Claflin, who returns as part of Peaky Blinders Season 6) ends in a bloody disaster with the deaths of his men.
Mosley, meanwhile, doesn't look any smarter or stronger than before. At the start of Peaky Blinders season 6, Tommy returns home from a failed suicide attempt.
He gets a call, "I presume you're wondering who stopped the killing," as a van dumps the bodies of its men in the doorway.
Since the doctor's attitude had something to do with Mosley and Diana, Oswald probably knew about the murder.
The upcoming Peaky Blinders film should provide a satisfactory answer, although based on Dr. Holford took aim at Tommy probably already knew.