Beneath the Tasman Sea, two parallel chains of underwater volcanoes have long posed a quiet riddle to geologists — twin signatures of fire in a place where only one should exist. A new study reveals that a single plume of superheated rock, rising from Earth's deep interior, splits when it encounters a sunken slab of ancient seafloor, escaping around its edges to feed both chains simultaneously over 40 million years. The discovery asks us to reconsider how we read the planet's past: if the deep Earth navigates obstacles and branches like a river finding its way, then the trails volcanoes leave