 All ten regular cast members were also retained for the second series, and two additional regular characters, Andrew Argyle (Dominic Mafham) and Kate Brady (Tamzin Malleson), were introduced.The third series saw a major overhaul in both cast and format, with the series being rebranded as "A&E", a new theme being introduced to the opening titles, and storylines focusing more heavily on the inter-personal relationships between the hospital's staff members.Although all twelve regular cast members returned, by the end of the series, eight had departed, with many receiving much less screen time than in previous series.