Greg had heard from Warrick and Grissom about the grave incident, where Nick had been buried practically alive. As a result, Nick formed claustrophobia. Greg always kept a careful eye on him, making sure he was okay and telling people off, kindly, if they got too close. He also knew Nick had the occasional panic attack or nightmare about it, and he was always there to provide comfort. It was one of the rare days where they weren't needed at the lab, and they needed groceries, so Greg had went out earlier to buy some. He put them away, going to check on Nick. Nick was sitting up, knees to his chest and hands grabbing his hair tightly. "Oh, Nicky." He sat next to Nick, frowning. "Baby, it's okay. I'm here now, you're okay."