Janitors are everywhere―in every business, on every campus―yet they're rarely seen. They work hard to keep our community's buildings, schools and public areas sanitary, in a relatively thankless job with few perks. Yet janitors can seem almost invisible to those that aren't watching, often cleaning at night when other workers have left the office and gone home.

In the new film "The Philosopher Kings," eight extraordinary janitors throw off the cloak of invisibility to give us an extraordinary look into their lives. Director Patrick Shen shows viewers the difference between having an education and possessing knowledge by spotlighting the artists, humanitarians and thinkers who clean up--but do not study at-- some of the US's finest institutions of higher learning (such as Princeton University, Cornell University, University of California, Berkeley and Duke University).

Watch the movie's trailer:

This documentary about working people has its world premiere tonight at the AFI Theater in Silver Spring, MD. The film also has an encore screening scheduled for 1:15 p.m. on Sunday, June 21, in the same location. It is one of 11 films competing at the 2009 AFI-Discovery Channel Silverdocs Documentary Festival for the prestigious Sterling US Feature Award. For more information on the movie, visit www.philosopherkingsmovie.com.