Overview
The third machine is a Project Remus device in “The Third Machine.” It is designed for dimensional contact and contains a focusing chamber, tuning aperture, channeling rods, and controls capable of concentrating enormous energy.
Role
Raymond Hayworth uses the third machine to reveal a signal from another world. His attempt to send an immediate return transmission causes an interdimensional collision that kills him and leaves the chamber irradiated.
Years later, the third machine activates again and allows Helen Fenton to speak with Helen Hayworth in a parallel Project Remus facility. The two Helens rebuild the alpha machine into a physical bridge, but the bridge kills beta John Fenton during the first crossing attempt.
The bridge later destabilizes and separates the alpha and beta worlds in time. Helen Fenton secretly reopens it after twenty alpha days, only to discover that two beta years have passed. After Helen Hayworth crosses into the alpha facility, the bridge closes and leaves Helen Fenton trapped in the beta world.