I enjoyed this novella. The Viscount, Flynn, is accompanied from a ball by Lady Emma Talbot when a friend of his is shot, this leads to Flynn finding out where his kidnapped brother is and leads to the rescue of said brother, meanwhile Emma is compromised and she isn't exactly unwilling to be led.
Viscount of Vice is a quick, cute novella, but it does pale in comparison to the first book of the series, which is completely amazing. However, if you were to read this one first (it really doesn't matter), you'll be introduced to Satin, the leader of the Covent Garden Cubs, who is the series villain. Henry Flynn's younger brother went missing when they were children, but he's thought he was dead until an investigator say he's found him. The young man thought to be Robert Flynn is dirty, malnourished and addicted to opium, which keeps him dependent on Satin. Of course, Flynn has a love interest in his best friend's sister, Lady Emma, who is kidnapped by Robert and must be rescued while also reuniting the two estranged brothers!
There is quite a lot going on in Viscount of Vice, but I did enjoy it. It's a pretty typical Historical Romance with the best friend's little sister is off limits trope. The two have been in love with each other since they first met, but Flynn doesn't think he's worthy of Emma. And Emma knows all about his reputation, and wants him anyway, but the two are never alone together (that simply wouldn't be proper!) to say how they feel. Then after the Robert fiasco, the two can never go back to simply being polite, as their feelings have ignited! I wasn't fully invested in their romance, as it happens far too quickly, but I loved that proposal scene at the end! Too funny!