1. What prompts the boys to decide what they're going to do today?

1. They are bouncing on a trampoline, and Ferb stays up for a long time because he has a personal anti-gravity device

2. What are they trying to do?

1. They build an anti-gravity device and use it to make a bunch of floating trampolines

3. How does Perry get to his lair? Or disappear? Anything weird about how he's given his mission?

1. there was a secret trap door through one of the basement stairs
2. Doof has a shopping list that is an anagram for the word EVIL

4. How does Doofenschmirz trap Perry?

1. a recorded message gets him to step on his flying platform thing and there are foot loops to trap Perry's feet

5. What made Doof decide to build his inator?

1. he says that lies hold society together, so

6. What inator did he build and what does he hope to accomplish with it?

1. Tell-the-truth-inator that forces people to tell the truth. It includes

7. What is Candace doing besides trying to bust the boys?

1. freaking out about having the Johnson family over for brunch
2. She loses her gravity but is still trying to act normal 

8. What is Mom trying to accomplish for the day?

1. have the Johnson family over for brunch

9. There are probably several times that Candace tries to show Mom what Phineas and Ferb are doing, but by sheer luck her Mom can't see it even though it's right in front of her face. How do these instances occur?

1. It was the reverse - Candace was trying to keep everyone from noticing that she was weightless

10. If Doof's invention fails, what causes that to happen? If it succeeds, in what way does this end up being a problem for him?

1. He accidentally gets himself shot with the tell-the-truth-inator. Also the statue of Abraham Lincoln goes wonko and starts fighting Doofenschmirtz

11. What keeps Doof's invention from breaking continuity?

1. It wasn't breaking continuity

12. What ends up cleaning up Phineas and Ferb's activities before Mom gets home?

1. Doof's flying thing being out of control smashes through and collects all the floating trampolines

13. What is the topic of the song?

1. "lies are the glue that hold society together"