Therein lies yet another reason I love The Princess Bride. The pacing is brilliant. We ease into the story, and then it's off to the races. But moments of humor and romance are all brought at just the right time to give us a rest. Consider the fire swamp scene.
Here Westley & Buttercup are, heading into the dreaded fire swamp. We know something bad is coming...just listen to the music! (You know, I've often said if life only came with a soundtrack, we'd know when to watch out for things!) Sure enough, the fire spurt erupts, as does Buttercup's dress. But Westley's calm as he puts the fire out, and his confident smile as he says, "There now, that wasn't so bad, was it?" brings the tension down. Next, the lightning sand swallows Buttercup, and the tension soars. Westley cuts a vine loose and dives in after her. Following are seconds that seem like lifetimes (and that allow the ROUS to come snuffing about), but then, music swells as Westley pulls them both free. We lie on the ground, gasping along with them, grateful for the few moments to recover. Finally they walk along, calm, in good humor, talking about how they've overcome the hazards even as Westley gracefully lifts Buttercup over said hazard. It's a lovely walk in the forest now. Until (ominous music, please), the ROUS attacks!

Oh, wait. Here comes Humperdink!
And on it goes, ebbing and flowing, just enough to keep us both engrossed and relieved. Of course, one of the greatest pacing tools is the scenes between the grandpa and grand son. (Remember, "Hold it! Hold it! Is this a kissing book?")
So how do we, as writers, ensure the right pacing in our books? Well, I have a few ideas. But first, let's hear from you.