[5] Dr. Simon Kress's (Beau Bridges) research for the government on Martian life is aborted because one of his specimens almost escapes into the natural environment.
In the meantime, Kress deals with growing discord with his wife (Helen Shaver) over financial troubles, his obsession with work and the stress of concealing the stolen Martian lifeforms from his former supervisors at the government lab.
Major John Skokes, a prisoner of the aliens, is thrown into a cell, where he encounters another captive - a young female cadet.
As their situation appears bleak, Skokes attempts to raise his fellow prisoner's spirits by telling her of a top secret plan to launch a sneak attack that might turn the tide of the war.
Suddenly, a guard enters the cell, and she willingly leaves, revealing that she is really an alien spy who is actually being slowly transformed back into her original form.
Jay (Jason London) and Hannah (Alyssa Milano) are in love, but she wants to stay celibate until marriage.
A lab assistant enters the room in time to see Adam smashing up the laboratory before crashing through a window and escaping, while Dr. Link is left dead.
Mina, Dr. Link's daughter, contacts a lawyer, Thurman Cutler (Leonard Nimoy), who pushes for a murder trial, insisting that Adam is his client and not simply a machine.
As it is being led away, Adam sees the prosecuting attorney in danger of being run over and rescues her, sacrificing its own life in the process.
FBI agent Jamie Pratt (Michelle Forbes) investigates a series of murders spanning a period of forty years that were all committed with the same gun.
A geneticist, Dr Martin Nodel (Ron Rifkin), is a researcher looking into introns, mysterious sections of DNA that he believes hold the secret to future evolution.
Becka in the end tricks her husband into touching it, but as he begins to be fatally electrocuted, she finally realizes just what she has done and tries to save him.
Joshua Hayward (David McCallum) & his daughter Sarah awake one morning to find a four-block section of their suburban neighborhood surrounded by a mysterious energy barrier.
Meanwhile, Joshua finds a way through the barrier and comes face-to-face with their captors, a slothful race who feel physical activity is beneath them.
The Trinues explain that all of the inhabitants of Joshua's neighborhood have been taken as part of a feasibility study into the suitability of humans for slavery, and, if they are found able to survive in the alien's native environment, the rest of Earth's population will also be enslaved.
They return to their own neighborhood, and Joshua explains the purpose of the energy barrier to the other residents, wondering what choice they have other than to serve as slaves.
Ray injects himself with a serum to temporarily enhance his sensory abilities (more like GRS people) in order to hunt him.
Alone in his Mercury capsule, he panicked and aborted the mission when a mysterious violet light penetrated the cockpit & began enveloping his body.
In the investigation that followed, no evidence could be found to support his story, leaving a blot on Harris' NASA record & his life in ruins.
Harris & Powers are joined on the flight by Martin Reese (Mackenzie Gray), a skeptical tabloid reporter, Lil Vaughn (Andrea Martin), an eccentric fashion mogul, and Ty & Barbara Chafey, young newlyweds who won a contest to travel on the space plane.
Aaron (Saul Rubinek) is an American lawyer of Polish ancestry who is obsessed with what happened to his family at the Auschwitz-Birkenau concentration camp and is sure that Robert Greene (Jan Rubeš), aka Karl Rademacher (Alex Zahara), was the commanding SS officer in charge of his part of that camp.
Aaron is able to do little to prove who Greene really is or prosecute him, until a mysterious man, Nicholas Prentice (Alex Diakun), starts giving him evidence: a jacket, a notebook & other items which he obtained by going back in time to 1944.
Prentice had witnessed Rademacher shoot someone at the beginning of the episode, and he is from the late 21st century, where time travel has been perfected.