Just before filming the first chase scene, which was filmed over several nights, John Barrowman sprained his ankle, forcing a quick rewrite which put Jack at the wheel of a car attempting to head off the suspect.
Gwen says,"Hi, I'm DI Cooper. This is DS Harper," and Harper gives her a dirty look. Detective Inspector (DI) outranks Detective Sergeant (DS).
Burn Gorman was absent for large chunks of the filming of this episode as his wife was giving birth to his son at the time.
"Bernie Harris, the Scarlet Pimpernell of Splott." 1905 novel The Scarlet Pimpernell, about a British nobleman who rescues French noblemen during the French Revolution's Reign of Terror. "They seek him here, they seek him there.....that damned elusive Pimpernell".
This episode takes place in 2007.