Ameylia's investigations would lead her to the place where Lelenthial was found. A rather suface part of Undersigil, near the not-so-secret tunnel that has a portal usually leading to one of Clangor's garrisons. After the Dusters and the Harmonium cleared the place, anything noteworthy was probably claimed by the spiders.
On the way back to Mirror's Will, however, she'd catch the Harmonium rushing to the Scriptorium, with words of a macabre just recently discovered. Many of Sigil's adventurous population would join them, and find several patrolmen closing off the entire city block of the Scriptorium. Through reputation or status, they were allowed in, and once inside, the sight that awaited them was nothing less of grim.
One of the old teachers of the Scriptorium was impaled with a bladed weapon and their head was missing. She was Identified as Salcis, a tiefling scholar and retired adventurer, like most of the teachers of the Scriptorium. The assistant headmaster was visibly disturbed, but helped those willing to help by answering questions and guiding investigators around the school, going so far as to follow through the steps of the Infinite Staircase and fetch several books and dossiers from the Scriptorium's own library. Several leads where discovered, ranging from Salcis's relationship with the previous victim, home address, her area of study, to even the nature of the killer itself. What else could be peeled from the scene and the information gathered remains to be seen.