Two neutron stars (the remnants of dead stars, compressed to the size of a city but weighing as much as the Sun) spiral around each other and eventually collide. At that moment, something between a black hole and a super-powered magnet is born: a field billions of times stronger than that of the most powerful MRI machine. From the poles of this object erupt 'magnetic towers'—streams of field lines resembling tornadoes, but instead of wind, the very fabric of spacetime is twisted within them.

Inside these towers, magnetic lines tear and reconnect, like rubber bands that are stretched and then suddenly released. This process, called magnetic reconnection, releases energy. But until now, it was unclear which particles become the 'projectiles' in this accelerator. It turns out that electrons and their antimatter counterparts, positrons, are not enough. They quickly lose speed, like a cyclist trying to accelerate through thick syrup: radiation instantly quenches their transverse motion. Something heavier is needed.

Enter protons. They are almost two thousand times more massive than electrons, and when the field accelerates them to even half the speed of light, things get interesting. Colliding with each other, protons produce short-lived particles — pions. These, in turn, decay into gamma-ray photons, which then produce electron-positron pairs. The result is a cascade reminiscent of a chain reaction in billiards: one ball hits two, those hit four, and so on. Each proton collision produces, on average, four new electron-positron pairs. This avalanche fills the tower with matter that later lights up as a powerful gamma-ray burst.

This mechanism not only explains the brightness of gamma-ray bursts but also predicts a neutrino 'tail' that could be caught by detectors like IceCube at the South Pole. If the source is within our galaxy or its nearest satellites (up to a hundred thousand light-years away), the signal would stand out against other cosmic noise. Thus, protons born in the fiery vortex of a merger become messengers of the most energetic events in the universe.