Three hours of Internet searching provides Eddie with the mysterious Rover's real-world address -- a Chinese restaurant.

Posing as "Agent Fleming" from the FCC, Cade goes to the restaurant and soon learns from the owner that her son, Stephen, has a ham radio rig in the basement. She takes Cade downstairs to see the boy and his sophisticated setup, which ties his radio directly into a nearby computer.

However, Stephen proves to be extremely wary, and when Cade spots a disk in the computer the boy grabs the disk and runs out into the bloody events already established in the episode teaser.

There's a change, though. As Cade tries to draw away the pursuit, a bright, swirling wormhole opens in front of him and an athletic young woman bounds out. She deals with the aliens quickly and effectively, then grabs Cade.

Unfortunately, as she grabs Cade, Joshua and another Gua grab Stephen.

After the opposing forces retreat, the mysterious woman is elated, crying, "I did it. I stopped it!"

Cade, however, is less cheerful than confused and worried about Stephen, whose capture doesn't seem to bother the woman at all. She tells Cade that she's come back in time to save his life and bring him to the future.

When Cade doesn't believe her, she produces evidence: an old newspaper clipping of his obituary and detailed knowledge of his last journal entry. After she shows that she's not a rapidly-healing alien by cutting her arm, she tells him a terrible story about the future, where the Gua invasion proved to be a smashing success.

Cade brings her back to where he and Eddie are camping. Eddie's equally skeptical, but her story seems to hold up.

Then, complications arise. As it turns out, the woman -- who introduces herself as Lizbeth -- can only remain in this time for two days. In that time, she's determined to bring Cade back, believing he can help her turn the battered human resistance around to defeat the Gua.

Cade, however, is not at all sure he wants to go to the future with her, especially before he finds a way to free Stephen from the aliens.

Always pragmatic, Eddie thinks he can trace the source of the original alien signal if he can get some of Stephen's high-end radio equipment. Once they know where the aliens are, it's a safe bet they'll be able to find the boy.

Lizbeth thinks the rescue attempt is an unnecessary risk and argues against it all the way back to the restaurant the next morning. She does provide a useful distraction with Stephen's mother while Cade slips in and finds some stuff the aliens missed while searching the place earlier.

Joshua, who still wants the disk back, intercepts them as they leave. Cade is understandably angry that Joshua set him up, but the ambiguous alien shrugs it off, saying, "Maybe you set yourself up. Maybe you're starting to get predictable."

After taking the wind out of Joshua's sails by telling him that he ends up on the humans' side, Lizbeth knocks the wind out of his lungs with a well-placed foot. She and Cade escape.

Using Stephen's equipment, Eddie's made some progress analyzing the alien signal, even though he still has no idea what it means. Lizbeth, who knows a little more about Gua codes, says they could probably crack the code if they work together for a few days, but they don't have that much time.

Cade won't abandon Stephen. He tells Lizbeth, "I don't want to live in a world where one life doesn't matter."

Eddie succeeds in tracing the original signal to Pioneer Plaza, while Lizbeth works on blending in by donning a business dress. It's the first time she's ever worn one, and her struggle with it amuses and embarrasses the boys. Lipstick is also a problem. Eddie has helpful makeup tips, but won't explain to Cade where he learned them.

When they make their way to the plaza, Lizbeth is struck by the beauty and peace of Cleveland. Cade introduces her to hot dogs, which she enjoys after he explains that they are not in fact made from dogs. It's a pleasant afternoon until they notice two Gua agents bringing Stephen's mother into a building.

Upstairs, Stephen is reunited with his mother, but it's not a happy reconciliation as the agents, convinced that neither knows anything useful, are now ready to eliminate them.

Surprisingly, Joshua orders his underlings to let the mother go. He has no interest in harming her, but he still has plans for Steven. Having spotting Cade and Lizbeth on the plaza below, the alien leader drags the boy to the window as a bargaining chip: a disk for a life.

Cade understands Joshua's message perfectly, but it's still a tough decision. If Joshua wants the disk this badly, the information must be critical, but at the end Cade's just not willing to sacrifice an innocent for it.

At least Lizbeth is beginning to understand why saving Stephen is such a big deal. Cade's present is a gentler place than her time, one where innocent lives still matter. She likes this time, and she likes Cade even more. She's thinking about staying.

Back at the camp, Lizbeth goes into Eddie's trailer to change back to her practical clothes. Hoping for a way out, Cade asks Eddie if the disk can be copied. It can't -- there's a virus bound into the Gua transmission that prevents copying. If they want Stephen back, they have to give up the disk.

Overhearing this, Lizbeth tries to swipe the disk, hoping it can be put to use in the future. Cade catches her doing it, and persuades her to give it back.

It's then that she truly realizes he won't be going back to the future with her. He in turn begs her to stay -- but she also knows where her duty lies. Sorrowfully, they fall into each other's arms.

By the time they emerge from the trailer, Eddie's almost fallen asleep in his chair. Lizbeth tells him she was honored to meet him. In her time, he's known as brilliant and wise man. Touched and flattered, Eddie almost volunteers to join her in the future.

They return to the street where Cade almost died. She urges him to go quickly, but there's always time for a hug before time travel. Then she's gone.

Cade and Joshua meet once more at the garage. Joshua has Stephen, and Cade has the disk. "How do I know that's really it?" asks Joshua.

Cade shrugs, and says, "You know."

The exchange is made, and Joshua answers Cade's question about what's on the disk -- information on the human identities of two hundred Gua operatives. It would have been a potent weapon in Cade's hands, and Joshua would have done anything to protect them.

He leaves Cade with a thought: "Maybe we're not so different, Foster."