Answer: We know Will has arrived in the lobby since the L button's light has gone out. We know that the dead's spirits depart the elevator in the lobby (along with the cigarette smoke), and Shawn's spirit asks Will if he'll "come" with them. Now that he's at the Lobby level and the elevator doors are open, Will must decide whether to exit the elevator and continue on his revenge mission or to alter his mind and refrain from pursuing retribution. We don't know anything else. The ending of this fantastic cliffhanger is then decided by each reader's interpretation of these facts.
Shawn's soul is asking Will if he is coming, which I interpret to mean if he is going to carry through his revenge scheme to the point of death. Will's plan to assassinate Riggs has been called into question during the elevator journey down. This reader hopes Will does not chose to do so. The author's conclusion, on the other hand, is strong because it does not neatly wrap things up and offer us the final outcome.
Explanation:
