Duality is the starting point for this collection of Luyken-like associations: his two sons at different locations perform small actions; signed a cross returns as three-dimensional shape; indoor and outdoor spaces. The soundtrack features the sounds of drumming on metal. The title lapels to Luyken's two sons.

In the early 1980s, Edward Luyken had his own studio on the Lijnbaansgracht in Amsterdam. He also lived in the studio. In Celvast, diary images from that period are combined with shots of performances.