Daniel refuses to let his daughter pay for his mistakes; Lee and Ash prepare to change the world; Anna is surprised by what she finds at the pharma company.
Daniel and Anna decide to go on a road trip that has the capacity to change the course of their lives forever.
Daniel discovers the price of defying Gubby; Lee and Ash go on a reconnaissance mission; Anna's reckless behavior comes to a head.
Daniel is confronted with the consequences of his actions; Lee's horizons widen when he meets Eve's friend, Ash; Anna is determined to get results at any cost.
Daniel is summoned by Gubby, Anna crosses a moral line, and Beth makes a horrifying realisation. Lee has an epiphany after meeting Eve.
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.