Elena tugged on Stefan's hand and pulled him to a stop. She'd had many years to adjust to being a vampire now and found herself growing stronger every day. Maybe even stronger than Stefan, despite his age his animal diet made him weaker than your average vampire but Elena could only drink from the vein, human blood.
She took his face in her hands and looked up at him imploringly. She could see the haunted horror in those dark eyes, the worry. She wished she could just kiss him and he could wake up in a world that was better somehow. But she couldn't fix everything and daylight, true daylight wouldn't be coming any time soon. Not until Klaus and Rebekah were stopped for good.
"We're going to find him, Stefan," she said seriously. "I promise you, we'll find him."
Despite their own petty dramas and personal relationships, the three of them loved each other in one way or another. And a reunion was long overdue. Elena knew that Stefan wouldn't be able to think clearly, wouldn't be able to breathe until he saw his brother again. And so she was determined to find him.