Symbolism, Imagery, Allegory
When Cam accepts his mission to save the universe from destruction, he is given an E-ticket to Disneyworld with magical powers. And when we say magical powers, we don't mean he gets to cut to the front of the line. Nope, check it out:
"I don't know if you've noticed, but I'm hooked up to an IV. I can barely move."
"Yeah. I can help you out a little there, cowboy. I've got something Dr. X left behind. One of his early experiments. Hold out your wrist?" I do and she hooks what looks like a big plastic watchband around it. "Your temporary pass. It'll keep the symptoms at bay and stabilize you for about two weeks. After that…"
"After that, what?"
She's not smiling anymore. "The prions will take over. They'll tear your mind apart the same way that dark energy will tear the world apart." (15.81-84)
The bracelet is like a little color-coded countdown of doom. As much as it represents strength—it supposedly "keeps the symptoms at bay" for a couple weeks—it also represents the passing of Cam's limited time. As Cam's mission continues, and as his disease progresses, the colors on the E-ticket start to fade next to each listed place:
We've been on the road for six hours when my right leg starts to twitch uncontrollably. The E-ticket's lost a little more color; Adventureland's totally gone, and the second line, Frontierland, is a hazy green. (21.42)
As the E-ticket fades, Cam knows his time is running out. And you know? As readers, we know, too. Thanks for the visual aid, Bray.