Toby Keith knows a good hook when he hears one. And no one weaves a tale quite like Clint Eastwood.

That the two were sharing a golf cart last year at Eastwood’s charity tournament in Pebble Beach, Calif. is both a testament to their friendship and a stroke of good fortune. The encounter led Keith to pen the beautifully haunting song that lingers at the end of The Mule.

Get the story of how Eastwood inspired the song here.