Nathan Carlson has barely slept since July 30.
"Ever since it happened, I haven't been able to get it out of my head," Carlson says haltingly. "I just don't know what to think of it, quite frankly."
The Edmonton ethno-historian is one of the world's leading experts on Windigo phenomenon, and the recent horrific beheading and alleged cannibalism on a Greyhound bus bound for Winnipeg from Edmonton rocked him to his very core.
As the grisly details of Tim McLean's last moments on Earth came to light in the following days, Carlson sank deeper and deeper into a fog of horror and revulsion.
Vince Weiguang Li is accused of abruptly attacking McLean, who by all accounts he didn't even know -- while McLean slept on the bus.
Up until a few days before the killing, Li held a part- time job delivering newspapers in Edmonton. He was well thought-of by his boss and considered a nice guy, if a bit quiet and shy.
On July 20 -- just 10 days before the killing -- Li delivered copies of the Sun that contained an extensive interview with Carlson about his research into the Windigo, a terrifying creature in native mythology that has a ravenous appetite for human flesh. It could take possession of people and turn them into cannibalistic monsters.
The two-page feature talked about how, in the late 1800s and into the 20th century, Windigo "encounters" haunted communities across northern Alberta and resulted in dozens of gruesome deaths.
In one case, a Cree trapper named Swift Runner was hanged after admitting to killing and eating his wife, children, brother and mother in the woods northeast of Edmonton in the winter of 1878-79.
Prior to being charged with murder, he had suffered screaming fits and nightmares, which he attributed to being possessed by a Windigo.
In several other cases, people banded together and killed individuals they feared were possessed by a Windigo. Often, they would decapitate the corpse and bury the head separate from the body in order to keep it from rising from the dead.
Carlson documented several cases in northern Alberta communities where people believing they were "turning Windigo" would go into convulsions, make terrifying animal sounds and beg their captors to kill them before they started eating people.
In last month's bus case, Li allegedly butchered McLean's body, brandishing the victim's severed head at the men who trapped him on the bus until police could arrive.
He was later accused of eating McLean's flesh.
When he appeared in a Portage La Prairie courthouse on charges of second-degree murder, the only words Li reportedly uttered were pleas for someone to kill him.
A lot of his reported behaviour eerily mirrors the Windigo cases recounted in the newspaper feature that Li helped deliver to Edmonton homes just days before McLean was killed, one of the most gruesome slayings in modern Canadian history.
Several media reports called McLean's killing unprecedented - an unspeakable, random attack the likes of which has never been seen in Canada.
But Carlson knows better.
"There are just too many parallels," he says.
"I can't say there's definite connection, but there are just too many coincidences.
"It's beyond eerie."