An Alternative Answer
The afternoon after the night between Raven and Maria, the mansion's deconstruction had already begun under Tan's watchful eyes. But before the walls could be taken down, Erika had to purify the entire place, ensuring the safety of workers from the mummified humanoids.
Taking the workers with her to the basement as it was infested with the worst of the horrors, Erika was busy with Amedith as well as Liliyana, all the while, the rest of the party was hanging out in the mansion's garden. Not merely because it was a nice place to spend a sunny day, but instead because of something peculiar that nobody had expected.