Book ~ "Ceremony" (1982) Robert B. Parker

From Goodreads ~ Pretty teenager April Kyle is in grown-up-trouble, involved with people who'd beat her up for a dollar and kill her for five. Now she's disappeared, last seen in the Combat Zone, that side of Boston where nothing's proper, especially the sex for sale.

With Hawk, his sidekick, Spenser takes on the whole X-rated industry. From a specialty whorehouse in Providence to stylish Back Bay bordellos, he pits muscle and wit against bullets and brawn until he finds what he's looking for: April Kyle, little girl lost.

Spenser is a private detective in Boston and has been hired by the Kyles to find their missing teenage daughter, April, who they suspect is working as a prostitute.  Spenser finds April and she is indeed working as a prostitute.  Though Spenser isn't making her go home, she takes off from him.  As Spenser keeps digging, he discovers the person of influence behind providing teenage girls for prostitution and also the making of porno movies and he is determined to shut him down.

This is the ninth in the Spenser series (there are currently 46, with the last six written by Ace Atkins after Parker's death in 2010).  I've read many over the years (and have liked the series) and have started reading them from the beginning of the series.  Though it is part of a series, it works as a stand alone.  This book had an interesting but seedy premise and I didn't find the ending believable.

I liked the writing style ... I found it humorous at times.  Spenser is a tough guy with a wisecracking sense of humour.  Though this book was written and is set in 1982, it didn't seem that dated (there is reference to the "fuzz" and "bread", though).  It's written in first person perspective in Spenser's voice.  As a head's up, there is swearing.