An extremely prolific TV writer and producer, Brian Clemens was the creator and writer for some of the most popular action and adventure series of all time. A relative of writer Mark Twain, Clemens left school at 14 and was a weapons-training instructor during his national military service. While working as an advertising copywriter, he had a screenplay produced by BBC TV which brought him to the attention of film producers, the Danziger Brothers. He wrote many scripts for them, including B-movies like "The Betrayal" in 1957, as well as episodes of TV shows like the thriller, "The Vise." Clemens also wrote for many other shows in the late '50s and early '60s, including "Man from Interpol" and the spy drama, "Danger Man," starring Patrick McGoohan. In 1961, he began a long association with the iconic spy show, "The Avengers," which lasted seven seasons, acting as both producer and main writer for the series. Clemens's playful approach to the spy genre was an integral part of the show and became his trademark. He was the principal writer for the '70s horror show, "Thriller," and created the popular spy drama, "The Professionals," which lasted from 1977 until 1983. He also created the sci-fi crime show, "Bugs," a series about high-tech crime fighters that ran for four seasons beginning in 1995. Not content to rest on his laurels, Clemens created "CI5: The Professionals," an update of his older series, acting as producer and principal writer.