Tick-Tick-Tick is an episode of Kim Possible. Even though it is the fourth episode aired, it actually is the first episode chronologically.
Summary
While trying to print her term paper in time for class, Kim Possible lands herself in detention for being tardy for the third time that month (courtesy of Mr. Barkin). For Kim, this is a huge deal due to her status as a cheerleader and how it makes her look; however those worries are put on hold after Wade informs her of an incident in the Amazon. A bug researcher name Professor Akari had his experimental robotic tick stolen by an unknown thief for an unknown purpose. It was later revealed that the thief was named Shego and she was working under the employment of one Dr. Drakken. Back in Middleton, Kim served her first block of detention in Room 12 with other teens not of the same caliber but it was thankfully cut short by Rufus, Ron Stoppable's pet naked mole rat, who posed as a rampaging mutant that had broke free from the science lab. At fast food restaurant Bueno Nacho, Kim was given an update by Wade about a villain's lair in the Caribbean that linked back to Shego. Team Possible headed to the Caribbean lair but were immediately captured by Dr. Drakken and fed to man-eating sharks which Kim managed to apprehend with her Elastic Constricting Agent disguised as lipstick. Drakken planned to combine the robotic tick with his own nano-explosive as a threat weapon. Once attached to a victim, they would be at his mercy. Despite Drakken's plan, Kim was able to retrieve the plans for the robotic tick and flee Drakken's lair.
Upon returning to Middleton High, Mr. Barkin put Kim back into detention after identifying the mutant as a naked mole rat. Meanwhile back in the Caribbean, Drakken and Shego discovered that the missing tick was with Kim Possible. In detention, the other teens noticed a "zit" on Kim's nose that turned out to be the robotic tick. Immediately Kim ditched detention to find Ron and try to get the tick removed before it exploded. Unfortunately for her, Drakken as well as Mr. Barkin (with the teens in tow) engaged in hot pursuit of Kim and Ron. After seeking refuge in Bueno Nacho, Wade tells Kim that the only way to remove the tick was to burn the circuits. They are immediately interrupted by Shego for a moment but she is sat on by Big Mike, one of the kids in detention. Ron then thought of Diablo Hot Sauce and used it to remove the tick which exploded immediately after Kim threw it towards Drakken's hovercraft. Even though Drakken is thwarted, Kim still served her detention but this time she made friends with the people she previously deemed not cool (countering Barkin's objective of making detention a period of quiet suffering).