We build to create desirable places, -healthy places. Architecture insulates the healthy, desirable environment of the inside from the unhealthy world of the outside. Disease has therefore served as the historical rationale to exclude, situating the unhealthy person outside and the healthy person inside. Supplanting the local epidemic of the past, the 21st century global pandemic renders all universally vulnerable. Responding to this contemporary threat, this project explores the scenario where an infectious disease carrier arrives by plane to Dulles International Airport in Washington, D.C., and a possible architectural response. The subsequent project proposes an “Interstice”, an in-transit, infectious disease treatment and containment facility to be located within the airport’s grounds. Purposely built for the accommodation of contagious passengers, the Interstice derives space, material, and form, from the passage of people between the outside (the realm of the unhealthy) to the inside (a place of relative health).