Spy Mice: Secret Service is the second show within a show television series starring adventures that follows an organization of mice spies.
Spy Mice: Secret Service is about an organization of mice spies from around the world to protect the world from an evil rat professor, Ratfinger.
Billy: A mouse from America who is a high-ranking Spy Mouse. He is the leader of the spy team. He has a crush on Niki. His catchphrases are "Time to hit the road, Spy Mice!" and "I'm the bomb!" He is voiced by Jason Griffith.
Scott: A mouse from England who is the technological genius of the Spy Mice. He is very smart. His catchphrases are "All ready to go, Billy!" and "Chaps, we've got some work to do!" He is voiced by Andy Serkis.
Damian: A mouse from Canada who is a Spy Mouse-in-Training. He is somewhat of a klutz. His catchphrases are "No problem, eh? I'm fine!" and "Ready when you are, Billy!" He is voiced by Colin Mochrie.
Michelangelo: A mouse from Italy who is an operative of the Spy Mice. He ready to take on anything or anybody. His catchphrases are "I was born for action!" and "Mama mia! How did that happen?" He is voiced by Dwayne Hill.
Antoine: A mouse from France who is a paranormal specialist. He is the toughest mouse in the group. His catchphrases are "What's a mission without a paranormal specialist, non?" and "Sabotage!" He is voiced by Sean Cullen.
Reus: A mouse from Germany who likes to cook. He is the show's comic relief. He is voiced by Ron Rubin. His catchphrases are "I love missions! Isn't it fun, ja?" and "Let's go take the bad guys down!"
Ramsay: A mouse from Scotland who is a genius. He can tell whether food is poisoned or not. His catchphrases are "A bonny new mission! How exciting!" and "Och! We're on a roll, Billy, lad!" He is voiced by Maurice LaMarche.
Niki: A mouse from India who is fearless. She is capable of handling problems on her own. She has a crush on Billy. Her catchphrase are "Time for action!" and "How wonderful this mission is when you're around, Billy." She is voiced by Isabella Acres.
Ratfinger: A parody of Goldfinger and Bill Sykes from Oliver Twist, he is an evil rat loan shark who wants to take over the world and is always thinking about quick getting rich schemes. He can be grumpy and conceited at times. He is voiced by Robert Loggia.
Mission: Bank Robbery
Mission: Pool Trouble
Mission: Plane Disaster
Mission: Indianapolis Race
Mission: Monster Madness
Mission: Pharaoh's Tombstone
Mission: Elephant Rampage
Mission: Bank Robbery
Billy: When danger calls, that's when we strike!
Scott: Uh, Billy. I hate to interrupt you enthusiasm, but we need to take on those bad blokes right now! Those thievin' blokes, I tell ya.
Billy: Scott, get a hold of yourself. Those bad guys don't know we're already here.
Damian: Right, we should not make another sound.
Billy: Right you are, Damian!
Michelangelo: Um, Billy. If we keep standing here doing nothing, we should put our plan in action right now, amico.
Billy: Oh, yeah. Thanks for reminding me, Michelangelo.