For more than a decade, the possibility that Jupiter's moon Europa was venting its hidden ocean into space offered science a rare and tantalizing shortcut — a way to taste an alien sea without drilling through miles of ice. Now, the astronomers who made that 2014 claim have returned to their own data and found the signal dissolving into noise, their confidence falling from near-certainty to genuine ambiguity. It is not a failure of science but an expression of its deepest discipline: the willingness to unmake what we once believed we knew.