Every now and then a documentary breaks through to the mainstream and gets people talking or sometimes even ends up making the world a better place. Back in 2013, Blackfish did just that, exposing the poor treatment of orcas by SeaWorld and putting pressure on them to phase out their killer whale shows. Now this year we may have a similar doc on our hands from veteran non-fiction filmmakers D.A. Pennebaker and Chris Hegedus (The War Room, Kings of Pastry). Unlocking the Cage follows the ongoing legal battle to essentially declare chimpanzees “human” in the eyes of the law and help put an end to their captivity. Much like James Marsh’s Project Nim, this looks to explore just how much we have in common with our closest living relatives. Unlocking the Cage premiered at Sundance and will also be at Hot Docs before debuting on HBO later this year; check out the trailer after the jump and see what you think.