In Hidden, the tenth installment of the House of Night series, we are taken back to the night of the reveal ritual when the gang led by Thanotos attempt to uncover the truth behind the death of Zoey's mother. Neferet has come to know that Aurox is not preventing the ritual from taking place. She sacrifices Dragon's feline, Shadowfax, to Darkness to strengthen her hold on Aurox and force him to do her bidding by killing Rephaim to distract Stevie Rae from performing the ritual. Neferet watches as the threads of Darkness subside, after gorging themselves on Neferet's sacrifice and notices one inadvertently cause a fire in the stables which she doesn't bother to prevent. As she leaves, Anastasia's cat, Guinevere, curls up next to Shadowfax's body and dies of a broken heart.
Lenobia is haunted by dreams of Martin's death and his promise to find her again. She wonders if he has found her in the guise of Travis Bishop. Her dreams are interrupted by the fire in the stable and Travis desperately trying to free the horses. Determined that she will not lose Martin again, she (along with Nicole, a rogue red fledgling) rescues Travis and her beloved horses.
Zoey, the gang and Thanotos return from the ritual to find the House of Night surrounded by the fire brigade and the stables in ruins. Upon finding the bodies of the two cats, Thanotos realises a dark ritual has taken place and reunites their spirits with both Dragon and Anastasia in the Otherworld. Thanatos asks Kalona to build a funeral pyre for Dragon and resolves to proclaim Kalona as Death's Warrior at Dragon's funeral.
A remorseful and despairing Aurox, on the run from Zoey and the gang, falls asleep at a stream from exhaustion only to be awoken by Grandma Redbird's singing. Sensing the conflict and loneliness in him, she invites him into her home and feeds and clothes him. Aurox is encouraged when she urges him to fight Darkness and Neferet's control and resolves to return to the House of Night and seek redemption for his actions. On arriving at the school he is distracted by a raven and falls down a hole under a tree.
Zoey is in turmoil since her vision of Heath in the seers stone and wonders how she can convince the others over what she saw. Shaylin is learning to discipher her True Sight gift and tells Zoey that she noticed a change in Nicole colours which lean less to Darkness and more to Light. She also warns Zoey that Erins colours are changing but less favourably. The gang are shocked when they see Neferet on the news attempting to instigate a war between humans and vampyres by claiming the House of Night as well as the red fledglings are a threat to the public. Aphrodite is shocked to discover that her father, Charles is also allied with Neferet. Neferet contacts Dallas and tells him to cause strife within the gang - possibly starting with Erin.
The House of Night hold their own press conference to dispel Neferet's claims by showing her out to be a disgruntled employee. The conference is a success. A furious Neferet blames Zoey and Aurox for her plans backfiring. Realising that Aurox has turned against her because Linda Heffer was an imperfect sacrifice, she sets out to rectify her mistake by kidnapping Sylvia Redbird in order to sacrifice her to Darkness and create the perfect Vessel.
During Dragon's funeral, a distressed Aurox overhears Thanotos' speech and learns that he is the result of Neferet sacrificing Linda. He seeks refuge with Grandma Redbird (as she is the only one to accept him) but is horrified when he discovers signs of a struggle at her house and realises that she's been taken by Neferet. He returns to the House of Night to warn Zoey only to be attacked by Stark. Thanotos and Kalona break up the fight and are gravely concerned when they hear what Aurox has to say. Kalona volunteers to visit Neferet at her penthouse and find out where she is holding Grandma Redbird.
Before he sets out to Neferet's penthouse, Thanotos prays to Nyx to watch over her Warrior, Kalona. Kalona is shocked when he feels that Nyx is listening and realises how much he has missed her presence. Resolved to not let Nyx down he sets out on his mission.
At the penthouse, Kalona gets a frosty welcome from Neferet but charms his way into her good books. Kalona finds a semi conscious Sylvia Redbird in pain as the threads of Darkness commandeered by Neferet slice into her and try to bleed her dry. He realises that Sylvia is using the power of the earth to fight Darkness and this has thus allowed her to survive this long. Neferet sees through Kalona's ruse and orders Darkness to feed from Kalona and attack Sylvia. Kalona now having gone over to Light, discovers that Darkness no longer obeys him and struggles to free himself from their assault. Kalona's blood strenghthens them and Sylvia is unable to withstand this new onslaught. To prevent Darkness from feeding on him any longer, Kalona is forced to leave Sylvia and flee.
Aurox volunteers to rescue Sylvia but must go through several brutal trials in order to control the bull within him. Zoey and the gang use their elements to help him when it seems he's about to lose control. Before Aurox and the gang set out to rescue Sylvia, Kramisha gives Zoey a prophetic poem which appears to be a spell. Zoey has Shaylin stand in as her water element when it becomes clear that Erin has joined Dallas and Darkness.
Aurox arrives at the penthouse and is horrified to find Sylvia near death and in agony. Before he can free her, Neferet commands Aurox to release the beast and kill Sylvia. Despite the protection of the four elements Aurox manifests into the bull when Neferet realises the spirit element is preventing him from killing Sylvia, and orders Darkness to ensure Aurox obeys. Zoey realises that something is wrong when the elements return to their wielders and she and the gang race to the penthouse.
At the penthouse, Zoey uses the seers stone along with the spell Kramisha gave her and a shocked Neferet sees a vision of herself from the past in the mirror and breaks down weeping. Zoey urges Aurox to return to come back to them. While Neferet is distracted, Aurox charges towards her and the two fall over the balcony. Kalona saves Aurox but Neferet's body hits the ground below. Her body dissolves into spiders which scurry away and Zoey realises that their fight with Neferet is far from over. Stark saw Aurox's true form in the mirror when Zoey did the spell and urges her to repeat the spell and this time use the mirror on Aurox. The gang are shocked to see Heath. Aurox is mesmerised by his reflection and asks Zoey who Heath was to her. She replies, "Heath was my humanity. Now it looks like he's your humanity too."