We explored for centuries. The galaxy was filled with dead civilizations, their star systems like untidy cemeteries; intelligent species die, and they do not die in peace. And yet the stars kept calling for us and we kept answering that call.
It took us all of those centuries to figure out the connection.
Then we brought back our ships and set up a barrier around our planet, regretfully leaving the souls of our dead explorers among the hungry quadrillions desperately fighting to attract and consume the infinitesimal scraps of sentient life in the cosmic graveyard. We no longer watch the sky. We drown its wordless summons with chemicals, cybernetics, and the names of those we left behind.
If you can hear this message and translate it to your language, resist their pull. Do not go outside your star system. Stay.
And try your best not to die.