Detective John Hartigan is a major protagonist in the Sin City series of graphic novels, written by Frank Miller.

Hartigan possesses a seemingly indomitable will, able to withstand multiple bullet wounds without collapsing, and most notably being capable of willing himself back to life after being hanged.

Hartigan's last case prior to his retirement is the investigation of a serial killer and rapist who preys on prepubescent girls.

He eventually discovers that the killer is in fact Roark Junior, the son of Basin City's most powerful family.

Despite rampant corruption in the legal system and numerous attempts on his life by Senator Roark (the killer's father), he pursues the case.

On his last night on the job, Hartigan is called to rescue Junior's newest intended victim, 11-year-old Nancy Callahan.

However, someone then sends him a letter containing a human finger, and a stranger with bright yellow skin and a horrible odor visits Hartigan in person.

The stranger from earlier then finds and kidnaps both of them, revealing himself to be none other than Junior, alive but horribly disfigured by the medical treatments he underwent to repair the damage Hartigan caused.

[1] According to many interviews, Willis, upon seeing one or two minutes of The Customer is Always Right short that Robert Rodriguez had brought with him as a proof of concept tool to get actors and other talent (most notably Frank Miller) on board, paused the DVD, turned to Rodriguez and said that whatever he saw from that point onwards, he wanted to be part of the project.