A surgeon's morals are tested after he sets up an illicit clinic beneath London.

Daniel is forced to put Beth's former colleague Anna into an impossible position and the secrecy of the underground clinic is put in jeopardy.

Daniel finds he is moving far away from the man he thought he was, as dealing with London's most dangerous people starts to bring big problems.

Things become complicated between Daniel and Anna as they battle to save someone they both love, while Lee takes a risk that endangers them all.

Daniel's descent reaches new depths as he enters the world of organ trading. As police and gangsters close in, Jamie makes an error.

Hall and Moloney get a break in their hunt for Jamie. Daniel faces the ultimate question - how far will he go for someone he loves?

Daniel crosses a line from which he can never return. Lee's forced to make a big decision about the clinic.

As Mercy and Keith close in, Daniel, Lee and Anna discover just how far they'll go to save themselves.