The Bloodhound Boys are back for another adventure … but will they survive the deadliest race of all? Deep under the Earth’s crust, Skull River City is experiencing unexplained earthquakes AND impending doom. But Rocky and Vince have a challenge of their own - competing in the Monster Truck Grand Prix. A roller-coaster ride full of twits and turns, this lethal race will lead the Bloodhound Boys way off track. Will these undead friends be able to follow the signs back home in time to stop the earthquakes?