This week's episode of Casualty opened with guest characters Peter and Sonya having breakfast, however things soon took a turn for the worse.
But before the drama could unfold, viewers noticed that Peter Hawker was being played by actor Ciaran Griffiths, who has been in plenty of other popular shows.
Most notably, Ciaran played Mickey Maguire in cult classic Channel 4 show Shameless, and PC Gary Best in ITV police series The Bill.
Viewers took to Twitter with their findings, excited that the 37-year-old was back on their screens. One said: "He was in The Bill, right?" Another tweeted: "OMG it's Mickey from Channel 4's Shameless." A third wrote: "I know that guy.
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