At the beginning of John Wick 2: The John Awickens, the man is all set to retire ... again. Fortunately for Keanu Reeves and Lionsgate Entertainment Corporation, Wick is yanked out of retirement like a murderous Brett Favre due to a prior professional obligation. Mere hours after the events of the first film, foreign-sounding bad guy Santino D'Antonio presents Wick with a "Marker" -- basically a pinky promise shaped like a coin -- and demands Wick repay his debts by murdering D'Antonio's sister for him (he wants to take her seat in the big international crime syndicate).
Wick is still more than a bit torn up about the deaths of his wife and dog, so he refuses, at which point D'Antonio gives him some "motivation" by way of rocket grenade through the window. After his house turns into a ball of fire, Wick has no choice but to accept D'Antonio's contract on pain of death.
"But what if the rocket had killed him, boss?"
Wick spends several days preparing for the "impossible" assassination (he insists it can't be done), only to discover that the sister (Gianna) is totally willing to slash her own wrists as soon as he confronts her. He barely faces any resistance the entire mission; he kind of just walks in, at which point Gianna realizes that doing it herself is the best possible outcome. Another job well-done, Wick! At this point, he's probably bummed he blew so much money on a bulletproof dinner jacket and multiple weeks of doggy day care.