Jimmy Orders Nucky's Assassination (Season Two, Episode Seven)
He remained alive for five more episodes, but Jimmy Darmody signed his death warrant back in "Peg of Old" when, after goading from Eli, Al Capone, Lucky Luciano and Meyer Lansky, he gave the order to have his surrogate father killed during an event at Babette's Supper Club. Throughout the episode, it was clear that Jimmy regretted it, but his desire to be an important man in Atlantic City ultimately trumped his doing the right thing. Just before the hit man approaches Nucky, Jimmy walks up to the county treasurer in a weak attempt to justify his position: "It doesn't matter if you're right or wrong – you just have to make a decision." Nucky survives the shooting, the bullet only injuring his hand. But his relationship with Jimmy is irrevocably destroyed.