On a flight from a conference in Sri Lanka, attorney Jonathan Brooks is jolted from his seat by a sudden commotion. He rushes to assist an unconscious passenger, initiating CPR. But as the plane diverts to Oman, a second medical emergency grips the cabin. Moments before landing, the control tower issues a chilling order: the pilots must reverse course over the Arabian Sea.

Meanwhile, far from the turmoil in the skies, rival intelligence agencies are sent scrambling when a renowned researcher is found dead in her Shanghai high-rise, a virologist disappears in Berlin, and a clandestine lab deep in Sri Lanka’s mountains burns to the ground.

With fuel running low, Jonathan’s flight is redirected again, toward Goa. However, Indian authorities, now suspecting a dangerous, on-board contagion, reroute the aircraft to a remote airbase near New Delhi to impose a full-scale quarantine.