When the Lair floods, April goes to save Splinter, but he won't leave the sewer; to make matters worse, the mutant called Goldfin comes with a warning of staying out of his way, or else.

The mutant seahorse called Mustang Sally is going to flood the city and the only thing standing in his way are Leo and Pigeon Pete; being the leader isn't all what it's cracked up to be.