In north London, we follow Daren Francis, one of the UK's leading bowel cancer surgeons. Retired nurse Doris is in great pain with a tumour that Daren suspects is cancerous and blocking her bowel.
We go behind the mask to reveal what life is really like for consultant breast surgeon Sascha Dua, juggling the high-pressure world of the operating theatre with life as a single mum.
We follow consultant brain surgeon Omar Pathmanaban as he tackles a rare tumour that could be fatal, and also a complex and demanding procedure requiring surgery via the nose.
Following consultant heart surgeon Inder Birdi at the Cromwell Hospital as he performs open-heart surgery on 70-year-old retired engineer Mike and fixes 59-year-old Sara's leaking heart valve using state-of-the-art technology to operate through a 3cm incision.