Tom Ellis, the Welsh actor renowned for his portrayal of Colin Glass in the new CIA spinoff, has a compelling reason for his cautious approach towards the original FBI series before filming began. In an interview with Us Weekly, Ellis emphasized the importance of maintaining a clear distinction between the two shows, noting that they operate under vastly different principles and dynamics.
"The thrill of the contrasting agencies plays out more effectively when I'm less familiar with FBI's methods and operations," he explained. Despite this, Ellis admits to having dipped his toes into the show, acknowledging his long-standing awareness of Dick Wolf's TV empire. However, he consciously refrained from diving deeper into the content to maintain a fresh perspective for CIA.

"While there is some cross-pollination between the two shows, they are distinct entities that complement each other rather than being direct spinoffs," said Ellis, who stars in Tell Me Lies.
When contrasting CIA with FBI, Ellis observed a significant difference in their approaches. "FBI primarily deals with crimes that have already occurred, whereas CIA strives to prevent such crimes from happening in the first place," he clarified. "FBI is a highly visible and public face of law enforcement, serving as the poster boy for U.S. law enforcement. In contrast, CIA operates in the shadows, preferring anonymity and a stealthy, voyeuristic approach."
It's worth noting that FBI, which debuted on CBS in 2019, follows the agents of the Federal Bureau of Investigation in New York City. As the show gained immense popularity, CBS released spinoffs like FBI: Most Wanted (focusing on the Fugitive Task Force) and FBI: International.