Alex raises his eyebrows, then, sighing, pours out a small amount of the glowing substance into Neil's hand. "If you can ask about science, I should assume you're going to be fine." He meant it to come out humorous, dry, but the statement only holds affection.

"Pre-War toy," he answers anyway. "Kids thought the stuff was Nuka-Cola Quantum. Had a famous recall or something." He's distracted. Tired, yes, but-- Distracted. Relieved. His hand tightens on Neil's shoulder, and Alex tilts his head down, nuzzles lightly into the back of Neil's hair.