The Box of All Knowledge sat on a pedestal at the entrance to the galleries displaying Michael C. McMillen’s 40-year retrospective, and in its quiet deviousness, it set the tone for what followed. A small, pale blue trunk, scuffed, nicked and sealed with a rusted padlock, the 1997 sculpture passes persuasively as a found object, one with a mysterious function and rich history, a container for something impossible to contain. In its seamless fusion of the authoritative and the absurd, the materially seductive and the intellectually suspect, the piece typifies McMillen’s role as a sly procurer of wonder.

Born in Los Angeles in 1946, McMillen had an early predilection for science and from a young age routinely scavenged for castoffs in the alleys of Santa Monica. His ability to create objects and assemblages that invoke the past, with its textures, schema and conceptions of the future, fed into his work as a Hollywood propmaker in the ’70s and ’80s and fueled his art from the start. “Michael C. McMillen: Train of Thought,” organized by retiring Oakland curator Philip Linhares, touched down on the variety of mediums McMillen has engaged, usually in combination—sculpture, drawing, sound, assemblage, painting, installation and film. Works were clustered but dispersed throughout the museum’s galleries rather than confined to a dedicated space. This allowed for some interplay with pieces by other California artists, but not necessarily those most resonant with and influential on McMillen: Ed Kienholz, Llyn Foulkes, Gordon Wagner, George Herms. In spite of the diluted display, the poetic and psychic potency of McMillen’s work came through strongly.

His sculptures double as curiosities inflected with humor and history: a bottle, sealed with wax, purporting to contain Picasso’s last uttered words; a tall, narrow school locker, sealed shut, emitting the continuous sound of rushing water; a miniature building facade that reads equally as a mask, a sign deep in its entryway/mouth pointing “This Way to the Fun Zone.” In his films, some as short as 20 seconds, McMillen splices snippets of old dramas, sci-fi narratives, instructional reels, documentaries and his own footage to spin amusing, open-ended vignettes permeated with references to wartime maneuvers and Cold War fears.

Room-size installations penetrate the deepest, immersing viewers in a thoroughly convincing, alternate place and time through precise detailing and the deft melding of the found and fabricated. Visitors entered the dimly lit Pavilion of Rain (1987/2011) across a makeshift bridge over a broad, junk-studded moat. At once outpost, shelter, shanty and shrine, the small building was pieced together from sheets of corrugated metal, abandoned shutters, mismatched windows and grillwork. Fragments of old-looking signage self-caption the structure, and car parts cling to the exterior like barnacles. At regular intervals, overhead pipes shower the tinkerer’s meditational retreat with a steady, thrumming rain. Here and consistently throughout his work, McMillen effects a thrilling sense of temporal and physical dislocation, a transporting illusion crafted out of personal and collective memory.

Photo: View of Michael C.  McMillen’s Pavilion of Rain, 1987/2011; at Oakland Museum of California.