Starting on January 7th, the Shiv Crew short, Shadows Past, will be free for three days. Grab it, tell your friends, and get a little taste of Shiv crew. If you want to go straight to book one, SHIV CREW, you can find it here.
Shadows Past is book 5.5 but can be read at any time in the series. It will have the most impact if you read it after book 5, however.