Things are changing faster than anyone can keep up with. First, Helen's friend and financial backer, Richard Feliz, withdraws his support with an ominous hint at Helen's secret plans. Then, Helen discovers an ally in the former Hollow Earth insurrectionist known as Caleb, who approaches her with a plan to build a new kind of sanctuary for Abnormals, one that will serve as an intermediary step between Hollow Earth and mainstream surface society. She recalls Kate from Hollow Earth to ensure the refugees have what they need, and Kate is hopeful at the thought that she and her Abnormal fiance, Garris, may one day be able to live together on the surface. But Will won't be a part of the realization of this new homeland - Greg Addison has forcibly recruited Will to work for SCIU. Helen lets Will go with no fanfare, almost as if she hoped he would work for the other side. Will is furious that she won't let him in on her grand plan, but his anger doesn't move her to reveal her intentions.

Things are changing for Tesla, too - after being fired as head of SCIU, he found that all of his inventions had been stolen by the government agency. And Biggie, whose loyalty seems still to be suspect, is also swept away in the changing tide - he decides to leave the Sanctuary and live with the other Abnormals. It's a tearful moment for Magnus, but not so for Biggie - he says his goodbye with a stony demeanor.

Henry has finally cracked through SCIU's security system to discover their latest plunders. One, in Bolivia, catches Magnus's interest - it seems SCIU is after Quetzalcoatl, the winged serpent of legend, a beast that Gregory Magnus searched long and hard for. One attempt came shockingly close, but when Gregory returned from the expedition as the only survivor, he strictly forbade any further pursuance.

Magnus and Will rush to the SCIU site, where they find a team of scientists and thugs attempting to transport the deadly beast. Magnus tries to reason with their leader, but the serpent is soon free of its bindings and, in a flash, kills most of the SCIU team and strands Magnus and Will deep within a cave. Will was shot in the stomach and Magnus fears she may have broken ribs, but Magnus manages to find water and dress Will's wound. Within moments, both are recovering miraculously from their injuries - could it be that the legendary powers of healing and wisdom bequested by Quetzalcoatl are real?

It's hectic business as usual at the Sanctuary when a video missive comes in from Kate via the London Sanctuary. She has intel on a planned Abnormal attack on the surface, so Magnus drops everything sends Will across the pond. Biggie is on a mission to Hollow Earth and is not responding to their messages, but Magnus isn't worried, knowing he can take care of himself.

Kate debriefs Will and the two of them go to question Kate's source, who is being held captive and thus is reticent to reveal any information to the enemies of the Hollow Earth uprising. But when he discovers that his own organization executed an attack on one of its own cells, he reveals that the underground rebels were planning an attack on the convention that is to take place in Lisbon where SCIU will meet with its international counterparts to form an alliance and quash the Abnormal revolution.

Magnus awakes to find that the mind spider - the organic Praxian device that absorbs people's thoughts - has escaped from its containment unit. Based on the fact that the lock on the spider's cell was unmolested, Henry realizes that the mind spider is responsible for the multiple security glitches the Sanctuary has been having recently, and may have created a secret data branch, heavily protected by firewall after firewall. As Henry discovers this digital cache, Tesla arrives and demands to know how they found it.

In a volley of blame, the team discover that a sentient, organic nanite is loose in the security system and could take down not only the Sanctuary, but the whole world's computers unless they stop it, and the only way to do this is to transfer their minds into the digital world - a potentially fatal operation.