Over the next few days, apart from the second day of term, when Avada finally got to act like a senior and share some everyday knowledge and customs about Hogwarts and Hufflepuff with the new students—as last year's top Hufflepuff and third-best student in the school—he spent the rest of his time either recording Voldemort's mental energy or slowly chipping away at Professor Baker's seal.
He wasn't planning to contact Voldemort again just yet. Instead, he wanted to finish studying Psychodynamics and completely master the method of recording mental energy in writing before seeking Voldemort out again. Then he could observe Voldemort's mental energy up close while it was active and collect more samples of it in motion.
So he had to sacrifice his Defense Against the Dark Arts lessons, sneaking in notes on Voldemort's mental energy while the class was going on. Fortunately, Quirrell almost never called on anyone to answer questions, and Avada had a decent grasp of second-year material, so his quiz scores hadn't slipped. Otherwise, someone would surely have noticed something was up.
His research into mental energy also brought an unexpected bonus. As his knowledge grew, he could use Magic Sense to detect and make out more information. Then, while working on the seal one day, he was astonished to discover that the powerful enchantment had a back door specifically designed for his own mental energy!
At first, he was startled, thinking Professor Baker had secretly analyzed his mental energy. But after further investigation, he realized it was the effect of the drop of blood he had used back then. When he smeared blood on the book's cover, the claim that "only he could see the contents" really meant that the book's magical structure had been made to resonate with his mental energy.
His understanding