"Professor Rotwood's Thesis" is the seventh episode of American Dragon: Jake Long.
One night, Professor Rotwood managed to take a blurred picture of Jake and Huntsgirl fighting. The next day, in class, he handed out fliers saying he was offering a $500 reward for evidence of the magical creature that was loose in New York City.
While Jake, Trixie, and Spud were at Trixie's house, they (or Trixie) accidentally broke a vase. The three tried to find a way to buy another one. It also turned out the vase was $600. While trying to earn money, Jake brought up the idea of earning at least five hundred dollars. He decided to give Professor Rotwood a few pictures of himself in dragon form. After the evidence was rejected, he turned in his scales and it was still rejected.
On his way home, Jake spotted Huntsgirl trying to steal the gold from a leprechaun. While the two battled, Huntsgirl knocked Jake into a building and became unconscious. Trixie and Spud were down below trying to find a way to get more money.
While the two were thinking of ways, they spot the dragon, unaware it was also Jake, lying in the alley. They decided to turn him in for money.
When they turned him in to Professor Rotwood, they were rewarded cash. The two decided to go to Jake's house to tell him the news. After Haley let them into his room, they pondered on where he could be. When Spud sat down, he turned on the computer and they both spot images of Jake as a dragon and Jake forget deleted the images from his computer.They even had images of him "dragoning up." They found it unbelievable, yet decided to get him back from Professor Rotwood.
At his residence, he was denied a refund and Trixie and Spud went to Jake's Grandpa's shop. After finding out magical creatures existed, Trixie and Spud got help from Grandpa and Fu Dog. Fu Dog drove a taxi, while the others rode in the back.
After Professor Rotwood put oil behind the taxi, it swerved through the driveway and they were stuck in a traffic jam. Meanwhile, Trixie and Spud gave up all their money to a taxi driver to get them to where Professor Rotwood and Jake were.
Right when Professor Rotwood was talking to the other people, Trixie and Spud struggled to free Jake. They came up with a plan and when Professor Rotwood opened the back of the truck, there was Jake in a dragon mask, which he took off. After they arrested Professor Rotwood, Jake thanked Trixie and Spud for saving them.
Later, Jake was at the shop with Grandpa and Fu Dog. Fu Dog made a mind-erase potion to make Trixie and Spud forget every magical event that ever happened. Just before Jake arrived at Trixie's house, he found the leprechaun who thanked him with a piece of gold. Jake goes off to buy the replacement vase before going to Trixie's house.
They affirmed their loyalty and friendship to him. Before Jake went to hang out with Trixie and Spud, he dumped the potion in a plant and joined his best friends with a video game.
Meanwhile, in jail, Professor Rotwood had grown suspicious that Jake was the dragon.
- This is the first episode in which Trixie and Spud find out that Jake was the American Dragon.
- This is a Professor Rotwood was mentioned Dipper.