It is the cruelest kind of disappearance: not a plane that fell out of the sky in a storm, but a modern airliner with satellite tracking, redundant systems, and a veteran crew that simply stopped being where it was supposed to be — and then kept flying for nearly seven more hours into nowhere. On 8 March 2014, Malaysia Airlines Flight 370, a Boeing 777-200ER en route from Kuala Lumpur to Beijing with 239 people aboard, signed off from Malaysian air traffic control with the now-infamous "Good night, Malaysian three seven zero," and was never heard from on the radio again.

Here is what is not in dispute, because it sits in the official record. Minutes after that final transmission, the aircraft's transponder and ACARS reporting stopped. Malaysian and Thai military primary radar then tracked an unidentified contact making a hard turn back across the Malay Peninsula — the opposite direction from Beijing — threading up the Strait of Malacca before fading from coverage near the northern tip of Sumatra. This was not a plane that lost power and dropped. Someone, or something, turned it around and flew it deliberately back over land while its cooperative tracking systems were dark.

The hard evidence — the thing that turns this from a vanishing into a geometry problem — came from a place nobody designed for the purpose. The Inmarsat satellite over the Indian Ocean kept exchanging automated "handshakes" with the aircraft's satellite data unit roughly once an hour for the rest of the flight, even though no human was using the link to talk. By analyzing two physical fingerprints in those signals — the Burst Timing Offset, essentially the round-trip travel time of the radio pulse, and the Burst Frequency Offset, the Doppler shift caused by the plane's motion relative to the satellite — Inmarsat engineers reconstructed a series of arcs the aircraft must have been on at each ping. The Australian Transport Safety Bureau published this methodology in detail. The final, seventh arc placed MH370's last transmission in the remote southern Indian Ocean, thousands of kilometers off course, at the very edge of its fuel range.

Then the ocean started returning pieces. Beginning in July 2015, more than thirty fragments of debris washed up across the western Indian Ocean — Réunion, Mozambique, Mauritius, Tanzania, South Africa. The most important was a section of wing flaperon found on Réunion; French investigators confirmed it belonged to MH370 by part numbers traced through the maintenance chain. Drift-modeling of where those fragments came ashore, run independently by oceanographers, broadly agreed with the satellite arcs. The plane went down in the southern Indian Ocean. On that, the physics and the flotsam converge.

What the evidence does not give us is a reason, or a wreck. The Malaysian government's safety investigation, released in 2018, conceded it could not determine the cause and pointedly refused to rule out unlawful interference by a third party — extraordinary language for an official report. The deliberate turn, the powering-down of tracking, the long silent run to fuel exhaustion: every clue points to intention, and none of them points to a person or a motive. The two government-led seabed searches and a later private effort by the seafloor-mapping company Ocean Infinity covered more than 120,000 square kilometers of abyssal plain and found nothing.

The skeptic's discipline matters here, because MH370 is a magnet for the unfalsifiable. There is no credible evidence the plane was "shadowing" another jet to hide on radar, no evidence it was spirited to a secret base, no signal it landed anywhere. The data are actually consistent with a grimly simple story: a depressurization or a deliberate act incapacitated everyone aboard, and a ghost flight droned south on autopilot until the tanks ran dry. That fits the arcs. It also requires no exotic conspiracy — only a question we cannot answer.

And that is the part that refuses to close. We have a debris field's worth of physical proof that MH370 ended in the Indian Ocean, satellite mathematics precise enough to draw an arc across an ocean, and not one recovered black box, not one confirmed impact site, not one established reason for the turn that started it all. A machine built to be trackable made itself untrackable, talked to a satellite for seven hours after it should have been on the ground in Beijing, and took its answer down with it. Where, exactly, is the main wreckage — and who pointed the nose south?