The soundtrack starts when Juzu enters the Auction, attacks the ghouls and then looks up at the Madam (duration 09:40-10:52)
The soundtrack has not been publicly released as of yet. When the season is finished I assume we will know ;) (Though the ED and OP have been)
If my math is correct, the earliest it will be released is in 53 days and 4 hours (from when this is posted).
This is if they actually release the OST on that day, they might release it the weeks afterwards; who knows?