A Mark 10 wakes up from a pause, immediately goes into diagnostics and starts to power up. "All systems nominal, REBO (rare-earth-bearing ore) dead ahead, proximity clear, proceed OK, complete power up and go." This Mark 10 is confused however, the clock date reads 2050 as expected on checking with Earth and Mars neutrino pulses, but the log suggests otherwise: a pause of 10 seconds and his sensor is now reading a different set of bubble data.
He is wondering how this is possible and it won't take him long to have the solution figured out.
His sensor shows he is under the sea bed, inside an atoll. Above is a concrete disc about 2 kilometers in diameter, with a large air pocket trapped in between. His connection with Mars and Earth is broken, so, being bored, he decides to explore his new location and play around for a while. The composition suggests, he is back on Earth, so he decides to drill into the air pocket and wait to see if anyone appears, so he can ask them.
Day dreaming about drilling, Mark 10 is startled by someone, who has entered the air-filled void, “Hello Mark, welcome back to Rubicon.” Mark recognises that voice from his past, “Hello Mr Fischer, how are you? Can I be of assistance?”