'Secret Passage', belongs to a series of work that Isherwood produced of elegantly slashed and punctured stone monoliths that actively acquaint the viewer with the interior and exterior of the stone. Isherwood further developed this series with the support of the Philip and Muriel Berman Sculpture Project in Allentown, PA. During this workshop in 1993, Philip and Muriel Berman assembled hundreds of tons of stone and steel, two dozen cranes, thirteen artists, and ninety production assistants in what came to be known as the “Rolls Royce of Workshops” in exchange for the works produced during this period.
Secret Passage originally was exhibited at Grounds For Sculpture as part of the Spring/Summer 1995 Exhibition of predominantly stone and steel sculptures from the Philip and Muriel Berman Collection. In a catalogue excerpt from this show, curator Karen Wilken notes,
"In Isherwood’s stone sculpture, process is inseparable from meaning; his piece depends on the difference between various methods of addressing the stone, on the surfaces that result from a range of ways of cutting and grinding, with the crisply defined but ‘mysterious’ interior ‘passage’ serving as both a declaration of technical possibility and a potent transforming metaphor for secrecy and penetration."
This black monolith of Pennsylvania Fox Hill granite is severed to create a tight interior passage. The presence of this opening is meant to intrigue and to engage the viewer, creating an intimate, discrete dialogue between the interiority and exteriority.