No answer. But on his notebook, where there had been a blank page, there was now a single line written in shimmering ink:

Before Marco could protest, he shrank. The world dissolved into a swirling cloud of energy. He was no longer in his room; he was inside a system . A chemical system .

“Chemistry is not a list of facts. It is the story of how the universe holds itself together.”

They zipped out of the atom and into a dark forest. Two lonely atoms stood facing each other: a chlorine with seven arms (valence electrons) and another chlorine with seven arms.

Electra beamed. “You did it, Marco. You applied the First Law of Thermodynamics . Energy isn’t created or destroyed—just transformed.”