When loyal dog Mutt discovers that his owner and best friend Alice is set to board the RMS Titanic without him, he is determined to follow her across the ocean. With the help of King Leon the rat, Mutt sneaks aboard, but it isn't long before the Captain's cat, Clara, discovers the stowaway. Reluctantly, Clara agrees to help Mutt find Alice, on the condition that he help her look after a trio of abandoned kittens she found in a lifeboat. But when the unthinkable happens and the so-called unsinkable ship hits an iceberg, Mutt and his new friends have to race against the clock to reunite with their humans--and to survive.