In 2021, Sam and Ty are nervous because Gavin's contact is late. Suddenly, a blonde woman enters and sits down. He remembers something as she mentions she's the only one meeting him.

She pulls a gun on him and orders him to follow her out the back door. Ty and Sam try to follow them, but she nearly hits them with her car.

While Sam examines Gavin in 10,000 BC, the computer beeps, so Gavin responds they know that Sierra is Maya Schmidt. Of course, the computer plays more mind games and taunts they have Eve, and they'll trade it for the computer chip he remembered.

Sam returns with Maya and decides they need to send a message to Gavin in 2021 through the tarpits to say they need it. While Gavin thinks it's insane, they agree to try it. Just then, Izzy arrives, panicked, and shows them an explosive fire only a few miles away.

Sam helps people evacuate and tells Lucas that Gavin took Maya, Izzy, and Scott with him to the tar pits. He needs Lucas and Judah to help him.

Gavin tries to send a message in a bottle at the tar pits, but Scott fears being the recipient in 2021 since he was in a dark place then. Scott tells Maya what a great kid Petra is and how he hated losing her. He also inquires why she wanted to meet with him initially.

Lucas finds an injured wolf pup as the group walks to safety. While Sam wants to leave it, Lucas carries it as they continue on.

Back in 2021, Ty and Sam put an alert out for Gavin. Ty wants to get back to Paara. Sam wonders if his relationship with Riley has improved, and Ty assures him it has come a long way. 2021 Scott calls Gavin's phone, and Ty answers.

Scott has difficulty believing in time travel and doesn't like that no one can find Gavin. He refuses to give them the message, but Ty is determined to get Scott to trust them by preparing his favorite lunch.

Lucas finds Sam praying and is worried about him. He realizes after talking to him that Sam has been in a massive before. Sam tells him that he barely got his family out of a house fire when Riley was a child, and Lucas reminds him that he did save them.

Veronica shoots the dam, and after a few shots, it loosens and begins to flood.

Elena takes Gavin to the double aurora. One goes to 10,000 BC, and one to 1965, when the project originated. Ty and Sam arrive wanting to take the chip back with Ty. A fight ensues, with Gavin torn. Eventually, Ty gets the chip and goes through the blue aurora.

Scott sees the scars on Maya and confronts her alone. She returns to Izzy and Gavin, saying Scott was captured.

Veronica is scared she can't find Sam and Lucas, but she finally finds them in a cave. The dog has bonded with Sam. Ty has an emotional reunion with Sam and Gavin while Maya watches.

 

 

 

After they return, Ruth mentions the winds have changed direction, which could damage the fort. Ruth mentions a river and a dam nearby that could flood it. The men don't like this idea, but they agree to help when Veronica volunteers.

Gavin and his group watch the animals flee the fire. He has trouble breathing because of the smoke. Scott suggests soaking some of the extra t-shirts as filters. He and Maya go ahead as Izzy guides Gavin to rest.

She grows concerned as Gavin has another vision -- this time of Scott and a research paper written by him.

Back in 2021, Gavin demands to know who the mystery woman was. Her name is Elena, but she won't divulge how he knows him. She only reveals that the secret mission was to turn pilots into time traveling machines, and she ensured he was on that mission.

Elena explains once they were both on that mission they planned to destroy it together, but he's skeptical.

Back in 10,000 BC, Gavin questions Scott about the term paper, saying he had a memory about it and that the person who showed it to him had scars on their arm. The fire is worsening, so Scott goes to find Maya.

Elena takes Gavin to a safety deposit box and needs his thumbprint to help open the box. The microchip is inside.

Back in 10,000, Sam realizes the dam is broken, so Veronica suggests using Sam's gun to destroy the support beam and loosen the dam. The fire worsens, and the pup takes off in that direction. Sam chases it, and Lucas follows them.

2021 Scott remains rude to Ty, even after he prepared his favorite lunch. Ty remembered Scott confiding in him that he was messy and read comic books after his brother died, so he made his favorite grilled cheese as a comfort.

The guys recognized the flowers and realized Scott was mourning a break-up, and Scott was going to propose and now given up on himself and others. Ty and Sam convince him that he still has friends and they really need his help.

The note reads they need to find the microchip to save Eve. While it seems odd, Ty believes it's important.

Meanwhile, Elena tells Gavin that they are siblings, and he's overwhelmed.

In 10,000 BC, Sam rushes into the fire to save the wolf pup. Lucas wonders why he did that, and Sam admits he never saved the family dog in the house fire years ago and felt he let Riley down. He still feels like he is, but Lucas says he only will if they die.