During the late 19th century, the Noah's Ark Circus brings excitement and awe to London with their impressive feats and performances. However, the town is plagued with a strange pattern of missing children that coincides with the troupe's movements. To solve this mystery, the Queen dispatches her trusted Watchdog, Ciel Phantomhive, and his demonic butler, Sebastian Michaelis, to delve undercover into the circus and uncover their hidden agenda. This story arc takes place right after the Curry Contest Arc in the manga, concluding in episode 15 of the first season of the anime.