Taylor is off on a 24 hour reconnaissance mission outside the colony. With Washington out on another mission, Jim is placed in charge of the colony. Taylor promises Skye that upon his return, they'll go to Memorial Field together, to commemorate the third anniversary of Skye's parents passing away from syncillic fever.
Taylor goes to check on Lucas' equations, but runs into Mira, who is searching for the same thing. Mira takes Taylor hostage, and they both believe that Lucas has gotten closer to figuring out how to keep the portal freely open between the future and the past.
Meanwhile, Josh apologizes to Skye for getting her in trouble. Skye reminds Josh that Kara's still coming on the next pilgrimage, but Josh might have different priorities now.
Jim is determined to find the Sixers spy, and he's basically locked down the colony in order to flush out the mole. He's stopped Malcolm from communicating with his research teams because the mole might piggyback on the signal. Flashes of light are spotted coming from the jungle, with corresponding flashes coming from a construction area within Terra Nova. Jim and Reynolds hurry to the construction site, where Skye has cut her hand on the mirror shard she'd been using to contact the Sixers. A drop of her blood ends up in some paint thinner and she manages to get away before Jim and Reynolds find her. However, Jim has spotted that drop of blood.
Mira leads a hand-bound Taylor through the woods, saying that her transport isn't too far away. Taylor sees an opportunity when they pass near some plants with razor-sharp needles. He makes a break for it and rushes towards the plants, and Mira shoots at him with her sonic rifle. He's taken down but he also manages to grab one of the needles. Mira recaptures her prisoner, but Taylor now has a way to cut himself free from his cuffs.
Malcolm tells Elisabeth that it's almost past time to release the baby ankylosaurus back into the wild. Otherwise the mother may reject it. Elisabeth hesitates, knowing how much Zoe has grown attached to the dino. In another part of the clinic, Skye uses a healing device to clean up the nasty cut she has on her hand.
Jim takes the blood sample to the clinic and asks Elisabeth for help in extracting the DNA from the paint thinner. Elisabeth doesn't have the chemist skills to do this, but Malcolm does. Meanwhile, Reynolds speaks to Jim about his future intentions for Maddy.
Taylor and Mira share some tense small talk, as Taylor casually wonders how the Sixers managed to rig a pilgrimage. Mira replies that her employers had enough money to bribe their way on the list. The plan should not have taken this long to enact, and if Taylor hadn't figured out the Sixers's plan, Mira would've been back with her daughter in six months. Mira's daughter is sick, and her employers are taking good care of her while she's stuck in the past. Taylor takes advantage of a distraction and turns on Mira, attacking her and taking her prisoner. However, the pair realize they're being followed by slashers.
Jim grows frustrated with the dead ends he's facing when trying to flush out the Sixer mole, so he pleads with Malcolm to help extract the DNA from the blood sample. Malcolm initially refuses to help, so Jim decides to do the work himself. He smashes some equipment "accidentally", which convinces Malcolm to go through with the procedure.
Skye volunteers to join Josh's work detail outside the colony fence, but then she slips away and meets up with the Sixers. She hands over a chip with some intel about the colony, and in exchange, the Sixers will keep tending to her mother. Skye is allowed to see her mother, who is still sick with the fever. However, the Sixers apparently have the medicine required to keep her mother alive.
Taylor and Mira must work together to fight off the slashers. The two dinos are a mated couple in the middle of marking their territory. They see the humans as a threat and won't stop attacking until Taylor and Mira are dead. Taylor and Mira chase off the slashers with bows and flaming arrows. Realizing that they work well together and have similar goals, the pair believe they might have been allies in another universe. Meanwhile at the clinic, Skye sees the DNA analysis on the sample, and she contaminates it.
Elisabeth tells Jim that the sample was contaminated, and Jim knows that whomever destroyed the sample had to have access to the clinic. At least they know that the blood came from a female, which narrows the list down to less than 50 suspects.
The Shannons say goodbye to the baby ankylo, as it's released back into the wild and back to its mother. Taylor makes it back to Terra Nova and tells Jim about Lucas's equations. His son is close to finding an answer, which means the future of the colony might be in jeopardy. Taylor reminds Skye about their walk to Memorial Field, but notices that Skye is troubled. She shakes off his concerns, but Taylor still suspects something.