For a dominant hippo bull, his territory is his empire. By day he languishes confidently in his watery river habitat. Hes aggressive and territorial and his rule is indisputable But by night, dark forces grip the land and control slips to the predators. Now the hippos are at a disadvantage; they have huge bodies to fuel and most of their feeding takes place on land and at night. To get to their grazing lands they must leave the safety of the river and run the gauntlet of the flesh-eaters! The Don has been in control of this patch for ten years. Hes kept his family safe and free from imminent threat. But recently a gang has moved in on the land to the east of his empire wall. The Mohawks a ruthless clan of 12 lions. Theyre lean and mean and they take no prisoners. Their territories overlap both hippos and lions need the water and the land - and both of them feed at night! The Don and his family will now have to perform nighttime forays under the predatory surveillance of hungry flesh-eaters. Hippo is not often on the menu for lions, but big hunger needs big prey and with skilled teamwork, they could muster together to take one down. As if the nighttime predators arent enough to contend with, the Don must also keep a watchful eye on his territory by day. Its mating season and other bull hippos in the area are flexing their muscles and attempting to woo his females. Hes got the biggest set of canines in the Animal Kingdom and weighs 2.5 tonnes - hes custom built to defend his territory and his females. Territorial battles, romantic overtures, testosterone-laced feces-flinging and charging down deadly rivals its all in a days work if youre the hippo Don. But come nighttime, its a whole different ball game; powerless to guarantee the safety of his most vulnerable and cherished members, the Don may well lose a grip on his precious pod. Filmed with a fresh take on thermal and infrared imaging, Hippos after Dark transports the viewer into a realm seldom seen; where hippos expose their mysterious nocturnal activities through dazzling heat signatures, as they act out rarely witnessed behaviour. Its a secret world of hippo society seen in a whole new light, documenting both their glory and vulnerability. You havent really seen a hippo until youve seen a hippo after dark.