Complex sentence: Harry Pearce CBE is the fictional head of the Counter-Terrorism department of MI5, featured in the British television series, "Spooks", which is also known as MI5 in the United States.
Split into simpler sentences: Harry Pearce CBE is the fictional head of the Counter-Terrorism department of MI5, featured in the British television series, "Spooks". This program is also known as MI5 in the United States.