I encountered the Spectre first in my early Green Lantern readings when Hal Jordan came back via Geoff Johns and our Emerald warrior's soul was "grafted" to this avenging agent of God.
Since then I was curious about his origin and storyline and when Powerbooks marked this off as less 30%, well how can I not check it out.
Crispus Allen was a good cop and investigator when he was alive but after being killed on the job, God's agent of Justice called the Spectre needed a human host to perform his duty. Crispus was not ready and refused the offer. Without a host, the spirit took its frustration on humankind and went on a magical rampage leading up as one of the events prior to Infinite Crisis.
Since then Crispus had one year to think and after accepting the post, his task as the avenging spirit of justice, punishing sinners and evildoers for their crime begins and he learns that it is not as easy as punishing the guilty as singling them out based on priority or gravity of crime even if it leads to family.
If you want your reading dark, gritty and macabre then try this one for size. :)