Ayoungnewlywedcouplefindthemselvestrappedinanetworkofundergroundcaves.Withherhusbandinjured\,thenewbrideisforcedtofindherwaybacktothesurfaceinordertosavehislife.Intheprocess\,theydiscoveraterrifyingtruthaboutthequot;underneathquot;\,theyarenotalone.Somethingevilishuntingthem.