Ezra let out an exasperated breath. "Because we're not —" he started, but cut off when he realized any way to finish the sentence had the potential to sting — and to attract attention to their conversation from anyone who might be nearby in the library. But she knew what he was trying to say: they were nothing to each other. If they were family, if they were friends, if they were lovers, then she didn't have to have a reason. In those situations it was acceptable to want to do something solely for someone else. When the only conversations they'd had in the past year were a vicious argument and her showing up unannounced and uninvited in his bedroom after midnight, she didn't have the same rights. He didn't believe that this was wholly altruistic. He was afraid that she thought it would change things, whatever she said — afraid that she thought if she found the cure somewhere in here, they would marry. And he couldn't — couldn't give her hope for that, knowing she was going to be so disappointed when she kept hitting dead ends.

"It's not worth your time," he insisted.

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