Holed up in an intricate tunnel network, a guerrilla unit is tasked with defending a top-secret intelligence team against an American offensive. Shot in real subterranean locations, Tunnels: Sun in the Dark offers a riveting, claustrophobic vision of underground warfare. Vietnam, 1967. In a village outside Saigon, a multilayered network of tunnels is home to a paramilitary resistance unit under the command of Bay Theo. This scrappy and highly cohesive group makes do with basic resources and repurposed weapons. One day, they are visited by a military envoy for a special mission: to protect the newly arrived intelligence team against impending onslaught at all costs.