The Spy Teens were in their tree house waiting for a case to come their way because Sally hadn't called them in weeks. They figured something was up, so they decided to go spy mode. They pushed a secret button in their tree house and activated a spy setting in their tree house. Then, three chairs emerged from the ground; Judy sat down in hers and hacked into the SOOTS database. Then Judy pushed the ON button on her keyboard and activated the giant screen in their tree house. They used it to spy on SOOTS headquarters and investigate. Judy typed "Sally's Office" onto the screen and pushed ENTER. Judy said, "Sally may not know it, but she's about to give her recent spies an assignment."
The Spy Teens saw another group of spies walking into Sally's office. Sally said, "Welcome, agents. I trust that your last assignment was a great success." Lucy said, "You bet." Sally said, "Excellent. Now I have another mission for you." Judy said, "Mission time, guys." Kevin and Stella stood behind Judy and listened in with her. Sally said, "You are to investigate recent appearances of Mythical Greek Creatures." Tim said, "Like what?" Sally pushed a button and showed them pictures of Medusa, a Hydra, and a Centaur." Michele said, "But those creatures don't exist." Sally said, "Well, hours of surveillance say otherwise. So we need you three to go in and find out what's causing this and stop them." All of them said at the Stellae time, "We accept." Judy said, "You bet we accept." Judy hacked into the computer, deleted the file on their assignment, and put in their names instead. Then she re-assigned The Spy Teens, who were assigned the mission to a made-up assignment in The Amazonian Jungle. Stella said, "OK, we have our assignment, but what about our gadgets?" Judy said, "We're normally against this, but tonight we'll steal from Sally." Kevin said, "You're kidding?" Stella said, "I don't think we have a choice."
When it got dark, The Spy Teens used their disguise belts, changed their clothes to spy uniforms, and went to SOOTS headquarters. When they reached the final hallway, they ran to Sally's office but saw laser beams protecting it. Judy said, "Unfortunately, Sally doesn't want intruders in her office." Stella said, "Looks like we'll have to get in a hard way." The Spy Teens walked between the lasers and flipped over two, crossing each other. Then they shook by some of the lasers and leaped over a set of them. When they made it across, Stella looked at her watch, scanned the hall, and saw they were halfway through. Then they jumped over one laser, dunked, and went under another. Then they jumped over another laser, got on their knees, and crawled under ten of them. Then they quickly jumped over one, landed on their feet, ran over five of them, flew over one of them, and landed on their feet. Then they squeezed between two lasers, jumped over one, crawled under another, and quickly jumped over another. Then they flew over one of the lasers, shook by some of them, and leaped over two. Then they made it to Sally's office and used the laser setting on Judy's watch to cut a hole in the door and sneak in.
When they got in, they looked through Sally's gadget supply and took what they thought would be helpful. Judy said, "Let's see, Laser Lipstick." Kevin said, "Net Throwing Crossbow." Stella said, "Computerized Data Shades." Judy said, "Vanishing Skin Cream." Kevin said, "Sticky Gloves." Stella said, "Liquid Nitrogen Perfume." Judy said, "That should do it." Kevin said, "What about a ride?" Stella picked up a pair of keys on the desk and pushed the button. The wall moved away and showed them a helicopter they could take.
The Spy Teens landed their helicopter in Greece and started to investigate. The Spy Teens walked around town and started to feel an earthquake. Then they saw a Cyclops destroying the city. The Cyclops left, and The Spy Teens went after it. All three jumped in front of it, and the Cyclops stopped. Judy said, "You might want to consider the eye doctor because you're short one eye." The Cyclops grabbed Judy, threw her at Kevin and Stella, and took them out. Judy said, "We'll see about this." While fighting, the other spies searched The Amazon for any Greek Creatures. Lucy said, "Michele, do you even know where we are?" Michele said, "Not a clue." Tim said, "And we haven't seen anything since we arrived." They wondered if they were getting anywhere when they got to the river.
Meanwhile, Judy kicked the Cyclops down and then high-fived Kevin and Stella. Then the Cyclops got up and pushed all The Spy Teens out of the way. After they got slammed to the ground, The Spy Teens got up and saw the Cyclops getting away. Kevin said, "Time to bring this freak down." Kevin brought out his net-throwing crossbow and shot a net at The Cyclops. Then, the net wrapped around the Cyclops, and it fell to the ground. Judy said, "One Cyclops going down." After defeating the Cyclops, the town cheered and clapped for them while the person behind the case watched. The person said, "Looks like I'll have to toughen things up for these three."
The Spy Teens looked around Greece for clues that could lead them to the culprit but couldn't find any. Stella thought about something and got an idea. Stella said, "I think I know where to go." The Spy Teens walked to The Acheron River, and Stella started to walk in it. Judy said, "What are we doing here?" Stella said, "The Acheron River is 'The River of Hades,' so maybe if we locate him, we locate our villain." Then the water started to shake, and a giant dragon walked into the water. Stella said, "Here we go."
The Spy Teens ran up to the dragon, and it tried to eat them all at once. Then the dragon ate Judy, and both Kevin and Stella were shocked. Then the dragon started to feel strange because Judy took out her Laser Lipstick and used it to cut off the dragon's head and set herself free. Then she jumped down covered in slime, and her team held onto her. Then, the dragon's body got back up on its feet. The Spy Teens turned around and saw that the dragon had two heads. Stella shouted, "Hydra!" While they were fighting, the person behind the case watched them. Then Judy used her Laser Lipstick to destroy Hydra's heads, and Kevin and Stella watched. Then, four more grew back, and Judy destroyed all of them. Stella said, "Judy, stop!" Judy kept slicing the Hydra's heads, but it was no use. When Judy finished, The Hydra had 16 heads and was about to eat her. Stella said, "Judy, catch." Then Stella threw her The Liquid Nitrogen Perfume, Judy sprayed it, and The Hydra turned to solid ice. Then Judy flicked The Hydra, the ice cracked, and she destroyed it. After they killed The Hydra, the person watching got mad because his plan didn't work.
The next day, The Spy Teens were thinking the case through when a giant bird flew down from the sky. Stella looked up and pointed at the bird. Stella said, "Guys, Evil Fury straight ahead." Kevin said, "This looks like a job for The Net Throwing Crossbow." Kevin shot a net up in the air and caught The Fury. The villain saw what they did and got even madder than he already was. The villain said, "So these spies think they're so tough. I think not." The Spy Teens were walking around Greece, looking for clues and talking to each other. Stella said, "Not only are we in danger, but I bet all along Sally knew you would hack your way into taking this assignment." Judy said, "Alright, give it a rest. Once she finds out, she'll probably kill us. So, we must solve this case before anyone discovers what we're up to." The villain looked through his binoculars and saw The Spy Teens. The villain said, "Too late for that." The villain blew his whistle, and a Centaur and Minotaur ran up to them and grabbed them.
The Centaur and Minotaur brought The Spy Teens to their villain, and when they got kidnapped, Sally lost their connection. The alarm in Sally's office went off, and Sally read what was wrong with her computer. Sally said, "This says three of my spies are missing on The Greece Assignment." Sally traced the team she sent out to The Amazonian Jungle. Sally said, "But if they're missing, how do they appear on screen, and why are they in the Amazon?"
The Centaur and Minotaur put The Spy Teens in a cage on their ceiling and showed them their villain. A man walked in and saw The Spy Teens in his cell. Judy said, "And you are?" The guy said, "I'm Scar, a genius of Greek Mythology." Kevin said, "How are you doing this?" While Scar explained his plan, Stella took The Vanishing Skin Cream and rubbed some on the cage bars. Scar said, "It's simple. I have this Greek Mythology book, and I hooked my computer onto a copy machine. Then I copy the creature I want, push the button..." Scar punished the button on his computer, and The Spy Teens watched. Then, an Evil Pegasus came out of the Copy Machine, and Stella made three bars on the cage vanish. Scar said, "And boom, Evil Pegasus. I love being evil." Then Stella jumped out of the cell, shushed her team, and told them to come on. Then they jumped out of the cage and ran off before Scar noticed they were gone. Scar looked at the cell The Spy Teens were in and saw it was wide open, and The Spy Teens escaped. Scar said, "Those spies are smarter than I gave them credit for." Scar triggered the alarm while The Spy Teens were running, and all his monsters went looking for them.
The Spy Teens ran down the front hall and found the front door, but a handprint scanner protected it. Then Judy used her Laser Lipstick and cut a hole in the door. Then they ran out the hole they cut in the door and ran off, but an electric fence protected the hideout. The Spy Teens saw Scar and his creatures coming, so they ran back into his lair and hid from them. When Scar and his creatures saw the hole in the door, they looked outside but didn't see The Spy Teens. The Spy Teens had their Sticky Gloves on and hid on the ceiling. Scar said, "Find those spies and destroy them." Scar and his creatures left, and then The Spy Teens jumped down from the top, ran after Scar, and followed him to his copy machine. When Scar left, The Spy Teens approached the copy machine, and Stella put on her Computerized Data Shades.
Stella read the data on the copy machine and everything it could do. Stella said, "These Computerized Data Shades should tell me how to refuse the process, but I don't see anything." Judy said, "Let's just try this." Judy pointed her Laser Lipstick at the copy machine and destroyed it using her Laser Lipstick. Stella lifted her shades and said, "That works." When Judy broke the copy machine, she activated the alarm, and Scar entered the room. Scar yelled, "Creatures!"
Scar's creatures came and ran up to The Spy Teens, and The Spy Teens ran up to them. The Centaur kicked Judy away, The Minotaur pushed Kevin away, and the Evil Pegasus rammed Stella. Stella said, "These guys are tough. We'll need to round them up." Kevin said, "How?" Stella said, "With our gadgets." Judy ran up to The Centaur and used her Laser Lipstick to cut a hole in the floor, and when The Centaur ran to Judy, it fell down the hole. Then Kevin and The Minotaur ran up to each other, and Kevin used The Net Throwing Crossbow to catch it. Then it got wrapped in the net and tried to escape, but the trap was too strong for him. Then Evil Pegasus flew down to Stella, and she used her Liquid Nitrogen Perfume to freeze him. When Stella turned him into ice, he fell to the ground and broke into a million pieces. After they defeated his monsters, they saw Scar trying to get away, but Kevin held his Net Throwing Crossbow up to him. Kevin said, "Hey, where do you think you're going?" Kevin shot a net at Scar and caught him. Judy said, "Sorry, Scar, but your monster-making days are over."
After The Spy Teens caught Scar, they took him to SOOTS headquarters and locked him in jail. Then Sally caught them along with the team that mistakenly got sent to The Amazonian Jungle. The Spy Teens turned around, saw all four of them, and saw that they all looked pretty mad. Judy said, "Sally, we are so sorry, but we caught the person behind the Greece case." Sally said, "Let's see here. You hack into our system, steal, and go onto an assignment, unauthorized, I may add, break into my office, steal gadgets from me, send other agents on a false mission, and accomplish a mission that wasn't yours to take." Kevin said, "I think this means you don't want us around anymore." Stella said, "Come on, guys, let's go." While they were leaving, Sally stopped them. Sally said, "Are you kidding? What you did was wrong, but you saved the world." They all said at the Stellae time, "What!" Sally said, "And that's why I am grateful. Another job well done, agents. Many thanks." Stella said, "Just doing our job." Then Sally sent her other agents on an assignment while The Spy Teens went home.