Elliot's understanding did little to assuage David's guilt. David was Ghost Kid for Christ's sake. He's believed in spirits and things from the beyond since he was a teenager, and the one time it counted, the one time he was supposed to believe, he didn't. He shrugged off the understanding and let Elliot believe that he agreed with it, hoping that with the uncharacteristic bluntness came an uncharacteristic inability to read David's expressions. For once, he wanted to keep something to himself.
"I still should've," he left the sentence hanging there. "It's who I am. The ghost kid. I think..." he paused, "I think admitting that I saw your ghost would have meant admitting..." he choked on his words, but forced himself to say them anyway, "would've meant admitting you were dead. And I'm not ready... I don't want to..." He shook his head no, feeling like he didn't need to finish that sentence.
Saved a lot of lives. Great. "Yeah, but at the cost of the most important one!" he shouted. "It may seem cold but I would trade anyone in there if you could come back. Any of them! You're not just my brother, okay? You're... you were... you're my best friend!" He shook his head when Elliot told him that he'd get through it. "There was hope then. There was hope that we'd find each other but this? This is final! This is it. You're not... you're not coming back and I don't..." he choked on another sob. "I don't know if I can do it. I don't know if I can be alone forever..."
Shaking his head no, David looked down. As much as he didn't want to say goodbye to Elliot, he couldn't make him lead an eternal afterlife of watching the people he loved but not being able to really be with them. "This isn't fair," he said bitterly. "You didn't deserve to die. You were happy, or as happy as you could be in this world."
And then he brought up the reason he was happy. Rae.
He swallowed thickly and breathed a half-sigh. "I can try..." he paused, thinking for a second. "We can probably... I can try and help you get it to her yourself, if you want." It was a bittersweet moment, finding out everything you'd believed all your life to be true, but having to find out because it was your brother and your best friend that you lost. But David did know how. How to help Elliot get the message to Rae himself.