Mason Dash, operator of Earth Orbit street sweeper Kite, spots movement in a derelict space station where there should be none. Heading Earthward in his shuttle the last day of his three-month shift he detours, closing with the dark station. Something moving in there spooks him.

Dash, with the help of beautiful virtual personality Sheila, creates a plan to expose suspected hijackers. He believes Sheila is his secret but Janet, his brilliant AI expert spouse, informs him that she and Sheila are chums, and she's even added some experimental "adaptive" modules. While preparing a simulation "scenario" to carry into orbit next shift, Dash dozes off and Sheila stows away in the code, her new adaptive behaviors kicking in. No way she'll be left behind this trip.

Back in orbit Dash confirms the presence of intruders on the station, while inside the Kite computer systems there's turmoil. Emerging from deep in the data depths He_Ra has assembled a powerful force to seize control from the old Main Process.

Sheila splits attention between Dash outside and her own adventure inside Kite, getting a taste of romance and revolution. The tyrant He_Ra has taken a fancy to her and wants to expand to other orbital structures, like the nearby space casino, then perhaps to Earth.

Dash sends Sheila to the space station to scout. She finds not hijackers but a team of inept diplomats, preparing to receive humankind's first unearthly visitor.

Dash, doubtful they'll survive the encounter, would leave them to their fate when the alien, name of Troy, turns up. Troy's a working stiff too but is authorized to defend himself. His sensors detect a threat and he's armed with somepowerful planet-busting weapons.

Earth's fate is in the balance and only Dash, Sheila, Janet, and Kite, can prevent disaster.