THE KEY SOCKET
==============

The metal key fits the socket. The cabinet accepts it as if it has been
waiting since the 1970s.

The display changes:

    NODE 608 IDENTIFIED
    SURFACE MAINTENANCE AUTHORIZED
    OPERATOR ID: NOT REQUIRED

The key is not merely mechanical. It is a credential for the surface
node.

Three tones travel through the cabinet. A deeper door unlocks, but the
return line indicator turns amber.