In René Magritte’s La voix du sang, a large tree stands alone, backlit by a deep blue that recalls both dusk and dawn; the tree’s trunk opens to reveal a tiny townhouse, lit from within. What is Magritte saying about time and space? MUMOK looks at the work of Magritte, Max Ernst, Josef Hofmann, Pablo Picasso, Wassily Kandinsky, and many others in an exhibition that asks the question: Is modernism an epoch? In search of an answer, the curators consulted historical sources—four early “modernist” exhibitions and two books—all of which touch on temporal and spatial issues. —C.J.F.