We begin by rejoining Ashley, locked away in captivity, demanding to know what they have done to Henry. Whitcomb threatens to hurt him badly unless Ashley cooperates. The Cabal queen argues that they are fighting a "threat to the very survival of our species." When Ashley counters that most abnormals are peaceful and not a threat to anyone, Whitcomb taunts her : "Every abnormal we don't control is a threat, Ashley, despite your mother's propaganda. How many so-called peaceful abnormals have you destroyed?" Whitcomb goes on to claim that she likes Dr. Magnus, even used to admire her, but that "we are fighting for humanity's survival, and she's chosen the wrong side." "Are you ready," she asks Ashley, "to choose yours?"
The expeditionary force (Helen, Will, Druitt, Watson and Clara) survey the destroyed lost city of Bhalasaam. Watson surmises that it was destroyed approximately a hundred years earlier by an artillery bombardment, "likely a combined effort by Russian, French and Spanish forces." Helen calls it a slaughter of the last surviving vampires. The disappointment causes Druitt and Watson to begin verbally tearing away at each other, although it appears that Watson was just testing Druitt's loyalty.
Henry appears terrified as they work on him with injections and questions about his "condition". The doctor considers Henry "truly rare", both for the type of creature he is and for his control over the "stress triggers" that activate his mutation. They want to make him mutate. "No, please," pleads Henry, "you do not want to make that happen." The doctor just chuckles and continues turning the screws : "we intend to bring out your alter ego permanently. The knowledge we gain from you will be invaluable. Your kind have been hiding in the shadows for far too long, Mr. Foss. We're going to … bring you out into the light."
Will and Watson figure out where the Hall of Records must be and they head thru the ruins to continue their search. "Time, says Will, "you factored in time." Watson agrees, adding that "all visual clues have to be measured against multiple parameters", including time. "Like another dimension," marvels Will. Watson has given the profiler a new key to help unravel future mysteries. The team digs through the heavy, collapsed stones, searching for an entrance - at last breaking through to the interior below. As they prepare to enter the vampire's ancient labyrinth, Will is fired up : "I'm seriously geekin' out right now." Watson agrees. As they search the deep, empty stone corridors, discussing the vampire's heritage, they are startled to discover that they have been joined by Tesla, who is obviously very much alive. "Miss me," he inquires?
Although the team, especially Druitt (who is unhappy that he didn't succeed in killing Tesla last time), is skeptical to say the least, Nicola maintains they can't get the source blood without him. After powering up the lights for them, the gleeful, sarcastic vampire explains himself : "The Cabal want to turn the world into a war zone. Only the ancient blood can stop it. Yes, I do keep abreast of current events, thank you." He checks out the team and likes the spunky Carla, but coldly views Will ("a Protégé!") as "the mission's necessarily disposable item." It turns out that Tesla has been coming to the Hall for decades, but he has been unable to get the blood hidden by Magnus' father. Druitt doesn't trust Tesla : "Tell me, Nicola, if we do succeed, will you actually allow us take it away? We all know you have such wonderful designs for it, an army of newborn vampires being just the start." Nicola maintains that he has no hidden agenda for the blood, as no abnormals would survive the chaos which the Cabal wish to create. But he, in turn, knowing of John's health problems, doesn't trust Druitt either : "… tell me, John, are the rest of us to trust you once all is said and done? You who once put your own daughter in harm's way for just a drop of Helen's blood?"
Ashley wants to know why Whitcomb hasn't asked her any real questions yet. After being shown a prerecorded video of a peaceful Henry, Ashley accepts an offered drink, but warns Whitcomb : "If you put a truth serum in this, trust me, I will do a tap routine on this (electrified) floor rather than tell you anything." Meanwhile Henry is screaming in agony, his body trying to morph into his abnormal self as he struggles not to. He knows they'll kill him if he changes. The Doctor just smiles. "True," he purrs, "but we'll have learned so much in the process. Henry … this will be a noble end for you. Think of it as an organ donation after your death. What we learn from your alter ego may eventually save lives." Then he coldly orders an assistant to give Henry another shot, trying to push him over the edge.
The search party in the underground labyrinth at last comes to a large hall with a round table in the center. The table has an inscribed pentagram on the surface. Magnus recognizes that it requires her father's favorite password - her mother's birthday. The center rises, offering a small scroll with a map in Gregory's handwriting. The text is Latin, "his favorite language," smiles Helen. The map shows the locations of five tests, each attuned to the Five's special "gifts." Each test, if passed, rewards one with a key. Druitt and Tesla begin to go at it again, this time over Helen. "Honestly," says Magnus, trying to get them to focus, "I am surrounded by adolescents." They fan out, seeking their individual "assignments". Will and Clara enter a large room which "doesn't seem so bad," observes Clara. That is until the floor begins to give way : "Okay, this is bad."
Watson and Druitt come upon two doors next to each other, each labeled with similar Latin phrases. Druitt cannot force the doors open. Watson is convinced that a chamber containing a key lies behind one door, while certain death lies behind the other if Druitt teleports into the wrong one. Meanwhile, Will figures out that Clara needs to become invisible so as not to cast any shadows on the floor. She is too nervous to make it work, until she decides that both her and Will need to strip so that she can relax enough to become invisible. Will is aghast : "What? Well, people can see me. You can see me, that's not fair." But once he strips down to his shorts Clara becomes naked and quite invisible.
Helen and Tesla confront his test, a test he has tried and failed before. "Your father," he tells Helen, "managed to rig this tunnel here with a massive geomagnetic current. Voltage derived directly from the Earth. Do you have any idea how much electricity that is?" "He knew you were hard to kill," replies Helen. "Well, this just might do it," warns Tesla as he plunges ahead. Back in the Cabal lab, they have locked Henry up in a small metal room. He roars and pounds on the door, using just enough of his abnormal power to break it open, while maintaining his human control. "Awesome," he says as he leaves the room. Meanwhile, Tesla, snarling in pain, fights his way to the key at the end of the tunnel. Then he finds he has to fight his way back thru the current to exit. "Your father really didn't like me, did he," he asks. "You're an acquired taste," replies Helen.
Once again Watson is tormenting Druitt about his murderous history, although it is clear that remembering the past is torturous for both men. Then they return again to the question of the two doors and their Latin phrased labels : "Truth Lies" and "Lies Truth". Watson decides that, considering the subtleties of the language, "Lies Truth" is the correct door. As Druitt is uncertain as to whether his "old friend" could be exacting revenge for his "past actions", he grabs Watson to take him along, asking "Care to reconsider your choice?" But it is the right choice and they safely teleport into a room which contains a key. It occurs to Watson that Druitt can now leave him there to die, but the tormented teleporter reminds his old friend : "… as I once said, I have lost the taste for the sport." Once the pair teleport out together, the second door opens, revealing a key and what would have been a "room" of solid rock.
Ashley begins feeling drugged and woozy. Whitcomb orders an aide to "begin" as Ashley realizes that she has been outwitted. "And I'm afraid I did lie to you," crows Whitcomb, as the young Magnus passes out, "you're going to die today, Ashley". Gasping and groaning, Tesla makes it out of the tunnel alive, clutching his key. He is touched that Helen was concerned. She denies it, however, saying "You tried to kill me." "Yeah," shrugs Nicola, "but, you know, we all hurt the ones we love." Will urges Clara to focus on the goal as she again loses confidence and the entire room shakes from the shadow of her visible hand. Helen is surprised when her test appears to be nothing more than a simple eye scan. "Not much of a test," she says as a door opens. But once she enters the next room, the door closes again, sealing her inside, alone. As Magnus considers the obviously overly simple puzzle of 2 X 2, Will urges Clara to hurry as she grabs the key. Clara becomes visible momentarily as the floor gives way, but then she jumps the chasm and drags Will out of the room. Helen recognizes that the answer to her father's puzzle is infinity, and when she draws the infinity symbol in the bowl of sand, she gets her key and the door slides open again.
As much of the place begins to collapse, Druitt teleports back to the pentagram table with Watson. Will runs up in his shorts as the door behind him seals shut. Clara then becomes visible and begins dressing, complaining that her clothes are now filthy. Druitt and Watson stare at them with bemused smiles. Watson, appearing exhausted, says "Well done, William," apparently referencing the near naked Carla. Helen and Tesla race into the room while Will and Clara are still dressing. Helen frowns slightly as Will shakes his head "No." Each of them holds up their keys. As they place their keys in the proper spots, the rumbling stops and another door slides open, revealing the vial of source blood.
As they stare at the vial, Watson collapses, appearing to have aged a century instantly. His mechanized suit had given out at long last. "It's been failing for some time," he gasps, "… I knew … that this was a mission I would no return from, it's worth one last challenge, Helen." Just before he dies, Watson tells William "… there is something that we are not seeing. This was too easy. There is something else happening, something going on that we're no seeing. You must find the missing piece." And then he is gone.
Ashley awakens as she is being wheeled along on a gurney. She gasps when she realizes that it's Henry. She jumps to her feet saying "I need a gun." Henry hands her a gun and a cell phone. Neither of them wish to speak about what happened to them as they run towards a lab where Henry discovered a network interface. After Ashley calls her mom, signaling that they're ready for "dust-off", and Henry downloads what he believes to be the "Lazarus" files from the Cabal computer, armed men swarm into the room from two sides. Suddenly, however, Druitt teleports in and whisks them back to the safety of the Sanctuary. Then, after hugging her mom and thanking Druitt, Ashley collapses. Helen asks Henry "What the hell happened to her," and he says he doesn't know.
Up on the roof, Clara teases Will, thanking him for taking off his pants. When he tries to convince her to stay at the Sanctuary, she kisses him, saying that the view was too romantic to resist. In the infirmary, Helen and Druitt watch over Ashley, wondering what the Cabal did to her. Helen knows something is wrong. She thanks Druitt, who is obviously worried. As soon as Helen closes the door and leaves, Ashley's eyes pop open. Up on the roof, Will thinks he realizes what Watson meant and rushes off to warn Magnus. Suddenly, the vial of blood disappears just as Henry discovers the data they stole from the Cabal is fake. Helen marches into the library, confronting a surprised Druitt at gunpoint : "Isn't this just like you, John. Steal what we need the most, and then stick around to gloat about it." Druitt maintains that he has been in the library "the whole time." Slowly, it dawns on Magnus that it was not John, it was Ashley who stole the vial, just as Will runs in warning that they've been set-up. "We're too late," mourns Helen. On the other side of the planet, on Easter Island, Ashley teleports in to meet Whitcomb and hands her the vial of source blood. "Thank you, Ashley," says Whitcomb, "you've been everything we could have hoped for. Welcome to your rebirth."