In 1917 the U.S. Post Office seized a tiny envelope for its "subversive potential." Inside wasn't a bomb or a manifesto, just two ounces of human ash, which sat hidden in the National Archives for 70 years. That dust belonged to Joe Hill, the songwriter who coined "pie in the sky" and seemingly weaponized his own execution to become a mythic martyr.

This deep dive explores the tension between Hill's life and afterlife: the Swedish immigrant turned Wobbly, the controversial double murder conviction, the secret alibi he took to his grave, and the explosive circumstances of his death. We impartially examine the deeply flawed trial, the bullet wound he refused to explain, and the staggering calculus of a man who chose to become a symbol rather than a survivor.

• How he acted like an early viral meme creator, setting pro-labor lyrics to ...