Henry reluctantly shares some news on recent werewolf sightings in Northern England with Will, who straightaway convinces the dubious Henry to investigate them. The boys decide to keep the venture hush-hush - no telling Magnus, which is just as well, since she and Tesla have been obsessively trying to crack the code for the holographic city presented by Magnus's father, Gregory.
Will and Henry discover an institution that may be the epicenter of the sightings, and decide to "check" Henry in so they can investigate. They soon learn that the operators of the institution, a woman named Lillian and her niece, Erica, have amassed the region's Lycan clan - commonly known as werewolves - and are keeping them there on a strict diet of medication, to control the transformation, and fear, to keep them believing they need the meds. Henry tries to reason first with the patients, who are terrified of their own monstrous abilities, but when that doesn't work, he approaches Erica and Lillian, who are, themselves, Lycans. Although Erica wants to believe that what Henry says is true - that they're not natural killers - Lillian insists that the only way for everyone to be safe is to stay locked up. When Henry pushes the matter, Lillian has him carted away and injected with a drug, which Henry learns is violence-inducing - a practice Lillian uses to keep the fear coursing through her patients' veins, and which was also responsible for the recent attack in the institution where a man killed his best friend.
Magnus and Tesla have made some progress in discovering the holographic city's security code, but cracking it may be another matter, as the city detects their vampire blood and won't let them pass. Tesla forms an EM field around himself and Magnus - they try turning the virtual lock again, and, undetected, Magnus and Tesla slip through. What they find is remarkable: An atlas of Earth, with three tunnels leading to the Earth's core. Could this be the location of the epic city?
Will, investigating on his own, has found the perpetrator of the recent attack, a former inpatient named Liam, who is scared and confused. Will comforts the man, who, in turn, helps Will to find a way to save Henry. Will slips in through a basement door to the treatment area of the facility, where a drugged, violent Henry is ready to rampage. Will tries to reason with him, but to no avail. When it seems Will's life may be over, Erica and Lillian appear, and Erica transforms herself and leaps at Henry to keep him at bay. Soon, the drugs wear off, and the two Lycans return to their human forms. Lillian is terrified, but Erica has seen the range of her own power. Will calls in Declan, who sets things to rights at the institution by educating and freeing the patients, and dealing more harshly with Lillian.