“It’s impossible to live without reason.” A series of unreal scenarios.

After talking about being afraid of the sled dogs on trips to northern Canada with his dad when he was little, cut to Willem Dafoe bartending in northern Canada with sled dogs out back – I buy this, this is the most grounded the movie is gonna get. He’s watching a guy play video slots when they’re both suddenly attacked by dogs. A pregnant woman gets naked for him in front of her grandma. He goes into the basement and is suddenly sliding down a rock cliff… has conversations with other Willems Dafoe… by the time he sleds past a scene of mass executions towards a cave that becomes a madhouse of nudes, the movie still has no coherent reality and is nearly half over. Since there’s no real cause and effect, one scene bleeds or jerks into the next – he goes from tundra to desert to greenery, he has sex with a girl who turns into his mom, he sleeps outside then a fish talks to him. It almost has the unstuck-in-time feeling of Je T’aime X2, but it’s more unstuck in different Dafoe movies. There are a lot of bare-breasted women; Ferrara still knows what’s important. Maybe it’s meant to be a fragmented story of a haunted guy with guilt over his parents’ deaths and a failed marriage seeking solace in the black arts?

The best piece I’ve found is Neil Bahadur in In Review:

The figure of Dafoe’s character Clint himself seems to be on a quest to narrativize his own life, only just barely possessing a grasp on reality by journey’s end, having montaged his life’s experiences and ideas throughout the film’s runtime instead … The terror of Siberia (possibly Ferrara’s first true horror film) is in Clint’s back to nature resolve, only to discover that the dreams of the 60s have shattered and nature is nothing if not ruthless. The true horror is determinism — the entire film is driven by an anxiety that people cannot shake their past … not just in choice but even in their own genetic code.