Having waved goodbye to Hagrid, Rowan pretends to return to the castle, before circling Hagrid's hut and the frozen pumpkin patch. The Forbidden Forest trees are bare and creak eerily with the night chill. The bright full moon casts long shadows across the ground causing shadows to merge and seemly move on their own. Near the edge of the Forbidden Forest, she comes to a halt and raises her wand. With her desires and thoughts firmly in mind, she says, "Expecto Patronum!"
A silver mist erupts from the tip of Rowan's wand to form a silvery Thestral flapping its wings. The Thestral flaps its wings harder and glides off through the Forbidden Forest with expert ease fluttering between the trees until its glistening glow vanishes plunging the forest dark once more.
The Forbidden Forest is rather silent as Rowan studies the starry night between the stark tree branches. After the death of Professor Zephyros, Nadira had wished to speak to Rowan regarding that which she had heard after Rowan's departure. However, Rowan would not permit Nadira to even step foot into Hogwarts nor did she tarry enough on the lake to have a discussion. It wasn't noticeable most of the time, but plenty of times she had felt unseen eyes upon her. It was a stark reminder that the castle was not safe, and she would not be the one to put Nadira in harm's way.
That and well, Rowan although paranoid had to acknowledge one very important fact. With their presentation ball coming up, she and Severus would need to select a partner to attend the ball with them. She could not deny the fact that a great deal of those eyes came from boys trying to assess their likelihood of behind asked or refused if they dared to ask. No matter how annoying she might find their gazes, she could not accuse them of being Hydra either.
Although Hogwarts wards were better and would keep out further intrusions from Hydra. Logically speaking, Hogwarts would not expulse those that were already vessels of Hydra. The best example is Quirrell and Potter himself. Despite Quirrell being possessed by Voldemort the wards did not activate nor kill Voldemort. The specter was forced to flee Hogwarts wounded and weak, but still very much in existence. And the matter of Potter being a living Horcrux was all too similar to the state of Hydra…. In other words, the wars though repaired were no guarantee of anything. And wards are tricky things like goblin contracts, they do exactly what they are set to do with no room for discrepancies in the stated clauses.
It had crossed Rowan's mind to use alternative means to find out the identity of those watching her. The house elves or the Hogwarts's portraits were options, but they were not feasible plans. The portraits could not be controlled by the students only the Headmaster could and to a very limited extent the Professors of the school. The portraits could interact with the student body but only if the portrait wished to do so.
Most of the portraits near the dungeons tended to be huffy characters and were unlikely to do as Rowan requested. Not even in Potter's timeline had Potter been able to do so, the best example was Sir Cadogan. The short, squat knight was a loud, boisterous character who challenged anyone who laughed at him with his sword and was incredibly frustrating to deal with when trying to enter the Gryffindor common room when he temporarily replaced the Fat Lady's portrait. In other words, if Potter hadn't had any luck much less would Rowan be successful.
The mobilization of the house elves was not a bad idea either, but once again there were constrictions. The house elves were bound by the Headmaster of Hogwarts and though they lived to serve the students that did not mean they would obey them as per the Headmasters wishes. Rowan could not ask the house elves to follow fellow students because she did not know specifically who to request that they be followed. In addition, it was against the house elves code to bring any potential harm to other students and for that very reason, they would not obey Rowan's request no matter her lineage. It was the same reason that prevented Tom Riddle from using the house elves at Hogwarts in his youth to commit vile acts. It was a necessity for the greater good, (the irony).
Furthermore, it was not as though the house elves were omnipotent either. The house elves had felt to an extent the Basilisk and yet had not been able to apprehend nor destroy it in Riddle's or in Potter's timeline. Their magic although powerful in some ways was rather weak in others. The very same issue applied to Hydra. The house elves could feel the wards breaking and even the presence of Hydra within the castle, but the house elves could not repair the wards nor identity the vessels of Hydra. Or more importantly, the Horcrux of Riddle that had been housed in the Room of Requirement nor had they been able to remove or bind the curse of Riddle on the post of the Defense Against the Dark Arts. The constraints upon the house elves were very much in place and the house elves of Hogwarts were bound to obey those constraints.
Although Nadira could command the house elves to an extent, she could not wield full power over the house elves and Hogwarts as the guardian of Hogwarts for that implied the official recognition of her existence as the guardian of Hogwarts. In other words, the Headmaster of Dumbledore would need to acknowledge Nadira as the Guardian of Hogwarts. And with so many unknown factors and dangers, the only source of protection for Nadira was that her existence remained unknown to their enemies. The longer Nadira remained hidden the more time Nadira had to grow in power. She would need every single grain of power to survive for Hydra would come for Nadira upon learning of her existence, and it would do all in its power to kill her, and it would vehemently try.
And Rowan had promised the Great Mother Snake to protect her egg. Sooner or later, she knew that Nadira would face Hydra, but until that time, Rowan would do all that she could protect the serpent. It was the only thing that she could do for Nadira as Nadira was still too young to sense the vessels of Hydra except for those that were in full possession and active.
It was also as to the reason why Rowan had not permitted Nadira to set one foot at Hogwarts until she found a way to contain Hydra's movements. She knew that Nadira had something crucial to tell her, but Rowan would not permit it. She could not tarry for long at the lake beyond simple messages and nor could she risk going under the lake lest she is ambushed on her way out. Meeting Professor Zephyros on the second night of the Hunter's Moon had been warning enough to her and especially now that she had lost the trail of Hydra's vessel.
There was still the possibility of Rowan using her great-aunt, Aunt Georgine, but what good would she do? Yes, her aunt was sensitive to magic casting and ward magic, but what use was that knowledge if it could not confirm, contain, nor prevent the continued existence of a vessel. As for the Hogwarts wards, her aunt could not alter the wards only the Headmaster could, and Dumbledore would not permit for the wards to be tampered with. (Not that Rowan could give her aunt Georgine a good reason to do so. That and well Georgine had almost broken the wards once in her youth and Dumbledore would most assuredly not allow for Georgine to experiment with the wards knowing her aunt's past.)
The second issue is that the vessels at Hogwarts are sneaky and virtually indistinguishable even by those that know the original vessel. Unless a vessel casts dark spells, her aunt would likely not notice considering the hundreds of children roaming about Hogwarts. With so many children wandering about even in the late hours, it was the perfect alibi for strange movements. Puberty is an awfully convenient excuse for almost everything….
Not to mention the same issue applied to Rowan's mapscape. Although her mind mapscape did reveal an individual's whereabouts it most assuredly did not reveal if said individual was a vessel or not remaining hidden from her view. Nor did she have the time to study her mapscape all day nor every night. It simply wasn't feasible considering her countless responsibilities during the day and into the late evening. Her night hours were spent researching and the rest in an exhausted sleep. It was surprising she had yet to collapse from the stress or lack of sleep for that matter….
Rowan had briefly considered other options such as Professor Mortimer, but realistically speaking if Terry couldn't sense anything amiss then his cousin was unlikely to do so. With Professor Mortimer to become the Head of Slytherin after the start of the new year, the Veela descended witch would be far too busy fulfilling her duties as the Slytherin Head of House.
Finally, Rowan had come to only one conclusion. If she couldn't find the vessel of Hydra, then she would bind Hydra's movements within Hogwarts. That meant, she needed to find someone that could to an extent sense Hydra. However, she knew of no one who was capable of such a feat and still lived. Yet she could not allow the precious opportunity to slip through her fingers. With Professor Zephyros' death, Hydra would be wary, and she would use that to her advantage.
Still, Nadira's mother, the Great Snake Mother had been able to sense the vessels of Hydra. On the other hand, Nadira was too young, but that did not exclude other magical beings from being able to at least sense the existence of Hydra on a subconscious level. That being said was easier said than done. Rowan could count the number of sentient magical creatures that she knew on one hand. The house elves, the merfolk, the goblins, Hagrid's Giant family, former werewolves, a half-vampire Lorcan D'Eath, Terry's Veela descended family, a dead Basilisk, the deceased Great Snake Mother, the Ancromantaula's, a herd Thestral's, and one other.
It was that final party that Rowan was precisely aiming for. They were a wild card to an extent, but if they accepted her request, it would be enough to constrict Hydra's movements at Hogwarts. It was a worthy gamble. She would roll the dice and bet her chips against the house.