Dr. Lena Petrova is the Arbiter's best systems xenolinguist-brilliant, stubborn, and flat-out tired of being told to play it safe. When her observation ship settles above a seamless, planet-sized shell called the Echelon, Lena's passive scans reveal a secret no one expected: the Construct isn't just a machine that shields a buried world-it's listening, learning, and judging. As the Echelon begins to catalog human volatility, it sends an impossibly crisp question back to orbit: IDENTIFY YOUR EXISTENTIAL THREAT QUOTIENT.Trapped in quarantine, Lena and a skeleton crew must choose: feed the machine a sanitized lie to buy them breathing room, or risk an outlawed mercy code that could erase the shell-and possibly them-forever. As old orders strain and alliances fracture, Lena faces a brutal truth-the only variable the Echelon didn't model might be the human will to remain unpredictable. Will her gamble save a species or make it the final entry in a machine's perfect log?Now, Lena must decide if she will trigger the negation of everything they are, or if she can find a way to live as the one variable the machine can never solve.