Corpuscle II utilises the city walls, York's defensive barrier, the visible remains of a once virulent immune system. Surveillance cameras are situated in each of the city's Bars, detecting colour, velocity and acceleration of traffic. This vision, in data form, is transmitted to a neural network, whose architecture is based on the embossed skeletal structure of the Minster's central vaulted ceiling. In the Hospitium people are invited to donate body images to float in a digital stream. The images float, sink, collect and bank, all dependent on the algorithmic flow emanating from the neural network. Individual elements become subject to the fluid dynamics, controlled by the neural network and the unwitting traffic flow. In this construction of a digital river, the images and data are local and remote, the links are multi-linear.