In the long project of understanding where we come from and what surrounds us, two space telescopes — one European, one American — have chosen collaboration over isolation. In March 2025, ESA's Euclid paused its survey of the distant universe to photograph the crowded heart of the Milky Way, gifting NASA's forthcoming Roman Space Telescope a two-year head start on its galactic survey. The gesture is small in duration but vast in implication: by sharing sight lines across different instruments and timescales, astronomers may finally glimpse the invisible wanderers of our galaxy — rogue planets,