Variety reports that TNT has canceled its lighthearted adventure series The Librarians tonight, declaring the show overdue after only four seasons on the air. A spin-off of a series of TV movies that originally began airing in 2004, the show tracked a group of world travelers, led by Rebecca Romjin, as they attempted to keep various powerful mystical artifacts out of evil hands. The series was notable both for its enjoyably light tone, and for the surprisingly high caliber of veteran TV talent—Bob Newhart, John Larroquette, Jane Curtin—it stocked its roster with.