As far as we can tell this sixth series about upper-crust DI Thomas Lynley and working class DS Barbara Havers might be the last one. Here's a short synopsis: Old wounds are reopened when Lynley investigates the disturbing death of his godson more than a decade after the boy's disappearance. Lynley is drawn into the case, leading him first to Rome and then headlong into the middle of a new murder inquiry in which Lynley himself becomes the prime suspect. Will Havers be able to save his skin? You can read a detailed review right here, please mind that there will definitely be spoilers!
Know Thine Enemy the second episode is all about a dramatic abduction case. Lynley and Havers's friendship is pushed to its limits in a high profile and chilling investigation into the disappearance of two teenage girls. Can Lynley save the life of the second victim and pin a murder charge on his suspects? You might want to read more details about this episode right here, but be warned there are spoilers!
Also if you'd like to take action against the axing of this series, you might want to consider writing to the BBC and state your personal point of view. Let's start with the BBC complaints department link here and then there's the BBC's Contact Us page here.
Update on August 9th, 2007 around 17:00 PM:
The BBC chose to change their broadcast plan 5 hours before the scheduled date. As they said in their TV announcement: "It'll be broadcast at a later date." I'll try my outermost to keep you updated on a somewhat reliable broadcast date. Keep your fingers crossed 
.