Little Green God of Agony is a thrice weekly comic that will run for eight weeks on Stephen King.com. Here's the official synopsis:
Katherine "Kat" MacDonald is an RN hired to care for wealthy client, Andrew Newsome, who has gone from doctor to doctor trying to find a quick cure for his lingering pain to no avail. She is convinced that he would overcome the injuries he sustained in an airplane crash but he is unwilling to endure the pain of physical therapy. In desperation, Newsome has hired a healer, Reverend Rideout, who promises to "expel" his pain.
So, if you're looking for some free Halloween horror, head over to King's official site and check out the first six pages of Little Green God of Agony.