Putting the pieces together which were restored in earlier episodes allows transmitting complete commands on the data uplink from Mission Control to the Apollo spacecraft receiver. Along the way, we learn how this worked, which was a glorious hack: the ground transmitted a sequence of button pushes to the Apollo Guidance Computer just as if they had been entered by the astronauts on board. This meant that the ground could do anything to the spacecraft that the crew could. This mode had to be enabled by a switch on-board, so the spacecraft was, when not receiving a scheduled uplink, not vulnerable to rogue commands sent by the Russkies or Moon Nazis from their far side base.