Ben Gates: It means that if something's wrong, those with the ability to take action have the responsibility to take action.
FBI: Here are your options. Door number one you go to prison for a very long time, door number two you help us get back the declaration from Ian, and you'll still go to prison for a very long time, but you'll feel good inside.
Ben Gates: Is there a door that doesn't lead to prision?
FBI: Someone's gotta go to prison, Ben.
Riley Poole: Asuming Ben's theory is correct and my tracking model's accurate, we should be getting very close. But don't go by me, I broke a shoelace this morning. It's a bad omen.
Ian How: Should we turn around and go home?
Ben Gates: Or we could just pull over and throw him out here.
Riley Poole: Ha, ha, ha, okay.
Ben Gates: Well Riley, you're not missing that small, windowless cubicle we found you in are you?
Riley Poole: No, no. Absolutely not.
Riley Poole: Who wants to go down the creepy tunnel inside the tomb first?
[Ben exhales sharply after unrolling the Declaration in Independence Hall.]
Riley Poole: What?
Ben Gates: It's just that... The last time this was here... It was being signed.
Answer: He doesn't simply assume "Beneath Parkington Lane" means beneath the church: Parkington Lane is the name etched on the tomb hiding the entrance to the tunnels. When he saw it, he naturally deduced what he had to do.
Sereenie