(Newser) – On Sept. 14, 2001, a 20something man calling himself Lyle Stevik got a room at the Lake Quinault Inn, a rundown motel on Washington's Olympic Peninsula. Three days later, the inn's maid discovered the man dead in his room. He had used a leather belt to hang himself from a metal coat rack attached to the wall in an alcove in the room. And so began the mystery of Lyle Stevik—a man who, as far as the system goes, did not exist. In a lengthy account in online magazine Mel, Kirk Pepi walks us through the "strange case" of Stevik, who "in death … became a 9/11 terrorist, a ghostly apparition, and an Internet superstar."

When law enforcement arrived at room 5 at the Lake Quinault Inn, they discovered a folded comment card with "for the room" written on it. Inside there was $160. They also found a crumpled piece of paper on which "suicide" was written in all caps. A Gideon Bible was bookmarked to John 12:33: This he said, signifying what death he should die. But what police didn't find is where the mystery lies. Stevik left no ID. Running his DNA, dental information, and fingerprints through law enforcement databases yielded nothing. Stevik appeared in no phone directory, search engine, electoral roll, or census. All roads led to dead ends. Eventually, the Stevik case went cold. But, years later, would-be detectives have again begun to attempt to unravel the mystery. Theories include:

The name Lyle Stevik was a pseudonym based on a character from a Joyce Carol Oates novel.

Stevik became suicidal after losing a loved one on 9/11 (which occurred three days before he checked in at the motel). Stevik feared WWIII was about to break out and decided to end it all. Or, Stevik was actually a 9/11 terrorist.

Stevik was driven to suicide by bulimia.

Whoever he was, at least two people have reported seeing his ghost at the Quinault Inn. Read the whole fascinating story here . (Read more mystery stories.)