Witches provide the central thread of Lux Æterna, a 51-minute experimental French-language work by Gaspar Noé that opens at Cinema Detroit this weekend. (Produced in 2019, it seems to have scored a U.S. release in conjunction to his more recent feature, the dementia-centered Vortex, which is currently playing in a brief run at the Historic Howell Theater, but nowhere nearer for the time being.)