Doug's Magic Act
At the end of this episode, Doug tells Patti how he feels about her and you can see she really likes him too. Then the handcuffs really were magic in the end because they opened right after Doug and Patti held hands and the big finish was all the confetti and flowers appearing.
In the end, rather then go to her practice, Patti changed her mind and wanted to spend the day with Doug. After this episode, I figured Doug and Patti were going to end up together in Season 4, but nothing ever happened. There was even the episode in Season 4 when they went on a date, but still, nothing ever happened. When Doug dropped Patti off home, it looked like they were about to kiss, but Patti rushed in the house.
I'm guessing Jim Jinkins was eventually going to have them end up together, but never got the chance or maybe he felt Doug and Patti were too young to be in a relationship, or maybe he felt it would change the show too much. Season 3 had a great finale with Doug and Patti ending up happily ever after.