"An adventure down under! Moldy mozzarella! A flock of sheep at Nicky's family's Australian ranch was losing all its wool, and no one knew why. Nicky and her friends the Thea Sisters headed to Australia and set off on a tour of the whole country in serch of clues. What happened next turned out to be a truly memorable outback adventure!"--Pages  of cover.
"When Paulina gets a phone call from home telling her that a friend is missing, the Thea Sisters travel to Peru to help solve the mystery. There, the five mice climb the Andes Mountains in search of a missing archaeologist. Along the way, they stumble upon clues leading them to a mysterious hidden city. Will the Thea Sisters find Paulina's friend, and the treasure of the Secret City?"--Page 4 of cover.
The Thea sisters are off to Japan on a cultural exchange program. While they're busy exploring Kyoto and admiring the beautiful cherry blossoms, a valuable item is stolen from their friend Kumi's family. Will the five mice be able to catch the thief?
"The Thea Sisters travel to New York to cheer for Nicky as she runs the Big Apple Marathon. While there, they visit Pamela's family and have a delicious dinner at the family's pizzeria. But when someone threatens to burn the restaurant down, can the Thea Sisters catch the troublemaker and solve the mystery?".
"In this fabumouse adventure, the Thea Sisters head to Alaska, where they're attending a conference held by an important ecological association. Their host and his family are native Alaskans, who show the mouselings their favorite games and activities. But soon there's trouble - the Thea Sisters discover that someone is upsetting the ecosystem by blowing up the ice with explosives! Can the Thea Sisters figure out what's going on and save the day?"...
"When the Thea Sisters' friend Bridget returns to Scotland for a family emergency, the five mice offer to help. And when Bridget goes missing, they have to rush to Scotland to find her! Along the way, the Thea Sisters encounter Celtic legends, cryptic messages, and hidden treasures on a trip that's full of surprises!" -- p.  of cover.
"An ancient treasure is in danger! The Thea Sisters have been invited to Egypt to participate in a fabumouse archeological excavation. They are helping to look for the legendary ancient Treasure of the Sun! A precious blue stone scarab may be the key to their search, and they work enthusiastically to uncover the past. But they also discover that thieves are after the hidden treasure. It's up to the Thea Sisters to stop them!".
"When the Thea Sisters' friend Ashvin is in trouble, they rush to his aid--in India! Ashvin has been working to return the monkeys living in the big city to their natural jungle environment. But the monkeys have suddenly started stealing jewels! Can the Thea Sisters figure out who is behind this terrible theft?"--P.  of cover.
"The Thea Sisters are boarding the famouse Orient Express for a journey from Paris to Istanbul! The train is on a special trip to return a precious wedding dress stolen years ago from an Istanbul museum. But there's a rumor that the mysterious Acrobat Thief will steal the gown from the moving train! The Thea Sisters are determined to foil this sneaky mouse's plans" -- p.  of cover.
"The Thea Sisters are headed to Italy for a ballet competition! But the mouselets aren't just there to dance -- they are there to investigate. A group is plotting to rig the prestigious contest, and the future of their new friend -- an aspiring ballerina -- is at stake! Can the Thea Sisters stop this scheme before it's too late?"--Page  of cover.
"The Thea Sisters are in Hawaii to compete in an international hula festival. The mouselets are having a great time -- until they learn that the festival is located on the side of a volcano that is about to erupt! No one else seems know about the danger. The Thea Sisters don't have any time to lose!"--P.  of cover.
The Thea Sisters are visiting friends in Spain when a mysterious theft turns their trip into an investigation! They end up hot on the trail of a secret treasure. The mouselets are in for an incredible adventure full of flamenco dance!
Attending an art class in the Netherlands, Violet journeys through the flower gardens, windmills and canals of Holland to investigate the untimely disappearance of her friend's father, a renowned botanist whose absence is linked to a rare black tulip.
" While on vacation in Greece, the Thea Sisters make friends with a company of actors who are rehearsing for a play that's about to open. When an actress sprains her ankle, Colette ends up standing in for her! But suddenly, right before the performance, the lead actor goes missing. Can the mouselets find him in time for the show to go on?" --
The Thea Sisters are in Russia for a figure-skating championship! When their new friend is falsely accused of theft and barred from competing, the five mice resolve to clear her name. Along the way, they discover ancient love letters that could be the key to finding the real culprit! But can they solve the mystery in time?
When one of the Thea Sisters' favorite mystery writers goes missing, the five mice travel to the author's native Iceland, where they reconstruct the dangerous plot of his latest novel in the icy terrain to piece together clues.
"The Thea Sisters are headed to Venice, Italy! They'll be there for the Carnival, an annual festival that's famouse for its elaborate masks. The mouselets love exploring the city's bridges and canals, and seeing the beautiful costumes mice wear to Carnival celebrations. But a mysterious thief strikes while they are there! Can they unmask him before the festival ends?"--Page 4 of cover.
While the Thea sisters are at the excavation site of a dig at Hierapolis, Professor Brenninger unearths a series of priceless and very old figurines, but the Thea Sisters think the discovery may be a scam and investigate.
Violet has been chosen to play in the orchestra for a production of Romeo and Juliet in London! The mouselets begin to notice strange things happening during rehearsals. Someone is trying to sabotage the production. Can the Sisters uncover the phantom before the show is ruined?
Taking a road trip to San Jose along Route 66 while stopping in Chicago, St. Louis, and other iconic cities, the Thea Sisters are dismayed to learn that an unknown saboteur has wiped a special video game project off of a programmer friend's computer.