"Reminiscing ~ The Vanished Fairy" is a Reminiscing-style track that plays in The Adventure of the Unbreakable Speckled Band when Nikomina Borschevic and Mitrov Stroganov recall the sudden killing of Kazuma Asōgi and Mitrov's subsequent plan to place the blame on Ryūnosuke Naruhodō.
It later plays in The Memoirs of the Clouded Kokoro when William Petenshy confesses to the murder of Duncan Ross.
Nikomina remembers how she panicked and pushed Asougi to his death.
The last thing Asōgi heard before Nikomina pushed him into his bedpost
Petenshy says he never meant to kill Ross.