Under the Steel Sky: the Thirteenth Quantum Chip

Lin Mo, the ace mecha pilot of the Interstellar Alliance, accidentally discovered that his brother Lin Shen, who had been missing for five years, had become an enemy scientist when he raided the flagship of the Mechanical Empire. When the chip containing the core data of the quantum engine fell into his hands, the holographic image left by his brother was a warning to "be careful of the alliance's top brass."