The Christmas Bones by Richard Amos

Balancing family life with being a kick-ass investigator is hard, especially when the holidays roll up.
Jake Winter and Dean Tseng are solving cases as PIAs (Paranormal Investigation Agents) in Amsterdam, as well as being fathers to their four-year-old daughter. With the festive season in full swing, everything should be calming down to make way for relaxing times with good food and presents delivered by Sinterklaas.
Right?
Since when was life ever that simple?
When a human body is discovered with every one of its bones missing, and creepy anti-supernatural protesters start lurking in the shadows with a sinister agenda, Jake and Dean are about to experience the nasty side of Christmas.