Talented and successful surgeon Daniel Milton has his world shattered when his wife Beth develops a fatal degenerative disease. After conventional treatment options run out, Daniel partners with the lonely yet resourceful Lee to start a literal Underground clinic in the vast network of tunnels beneath Temple Tube Station in London.
Cast: Marion Bailey, Tobi King Bakare, Daniel Mays, Lily Newmark, Hiten Patel, Chloe Pirrie, Mark Strong, Carice van Houten, Siena Kelly, Ryan McKen, Sam Hazeldine, Emma Carter, Carolina Main, Gabriel Gambetta, Jordan Long, Michael Salami
As Mercy and Keith close in, Daniel, Lee and Anna discover just how far they'll go to save themselves.
Daniel crosses a line from which he can never return. Lee's forced to make a big decision about the clinic. But will it be too late?
Hall and Maloney get a break in their hunt for Jamie. Daniel faces the ultimate question - how far will he go for someone he loves?
Daniel's descent reaches new depths as he enters the world of organ trading. As police and gangsters close in, Jamie makes an error.
Things grow complicated between Daniel and Anna as they battle to save someone they love. Lee takes a risk that endangers them all.
Daniel finds he's moving far away from the man he thought he was, as dealing with London's most dangerous people brings big problems.
The clinic's secrecy falls into jeopardy when Daniel puts Beth's ex-colleague Anna in an impossible position.
A surgeon's morals are tested after he sets up an illicit clinic beneath London to save his wife's life.