The Basement is filled with ETC card machines and with several racks of equipment devoid of corporate logos, inasmuch as they were designed and largely built by Lawrence Pritchard Waterhouse in Brisbane. When all of these things are hooked together in just the right way, they constitute a Digital Computer. Like a pipe organ, a Digital Computer is not so much a machine as a meta-machine that can be made into any of a number of different machines by changing its internal configuration. At the moment, Lawrence Pritchard Waterhouse is the only guy in the world who understands the Digital Computer well enough to actually do this, though he’s training a couple of Comstock’s ETC men to do it themselves. On the day in question, he is turning the Digital Computer into a machine for calculating the zeta function that he thinks is at the core of the cryptosystem called Azure or Pufferfish.