As Rex struggles to help his Carnotaurus overcome its fear of water, the D-Team gets word of a dinosaur appearance at Niagara Falls.  They reach the falls only to find the Alpha Gang already hot on the trail of this latest dinosaur, a Baryonyx. With Ace overwhelmed by the majestic falls, Rex is forced to stay on land with him while Max and Zoe board a pleasure cruise looking for the Baryonyx. When the Alpha Gang brings their dinosaur troops ashore, however, Rex must convince Ace to face his fears and confront them high atop the famous waterfall.