▁behind . ▁They ▁find ▁their ▁parents ' ▁w reck ed ▁ship ▁and ▁a ▁map ▁with ▁a ▁route ▁to ▁A ht oh all an , ▁a ▁myth ical ▁river ▁told ▁by ▁their ▁mother ▁to ▁contain ▁all ▁explan ations ▁of ▁the ▁past . ▁El sa ▁sends ▁Anna ▁and ▁O la f ▁away ▁to ▁safety ▁and ▁continues ▁alone . ▁She ▁enc oun ters ▁and ▁t ames ▁the ▁N ø kk , ▁the ▁Water ▁spirit ▁who ▁gu ards ▁the ▁sea ▁to ▁A ht oh all an . ▁Re aching ▁A ht oh all an , ▁a ▁gla cier , ▁El sa ▁disco vers ▁that ▁the ▁voice ▁calling ▁to ▁her ▁was ▁the ▁memory ▁of ▁young ▁Id una ' s ▁call ; ▁that ▁her ▁powers ▁were ▁a ▁gift ▁from ▁nature ▁because ▁of ▁Id una ' s ▁self less ▁act ▁of ▁saving ▁Ag n arr ▁and ▁that ▁El sa ▁herself ▁is ▁the ▁fifth ▁spirit . ▁ ▁El sa ▁then ▁lear ns ▁that ▁the ▁dam ▁was ▁built ▁as ▁a ▁r use ▁to ▁reduce ▁the ▁North uld ra ' s ▁resources ▁because ▁of ▁King ▁R une ard ' s ▁dis like ▁of ▁the ▁tribe ' s ▁connection ▁with ▁magic ▁and ▁his ▁intention ▁to ▁incorpor ate ▁the ▁region ▁into ▁his ▁kingdom . ▁She ▁also ▁lear ns ▁he ▁was ▁the ▁one ▁who ▁initi ated ▁the ▁conflict ▁by ▁killing ▁the ▁un ar med ▁leader ▁of ▁the ▁North uld ra . ▁El sa ▁sends ▁this ▁information ▁to ▁Anna ▁before ▁becoming ▁fro zen ▁due ▁to ▁vent uring ▁into ▁the ▁most ▁dangerous ▁part ▁of ▁A ht oh all