Ganymede Ocean.
20-thousand-odd feet below sea level, a black spherical sub could be seen descending the depths of the dark abyss.
"Captain, we are quickly approaching the 30-thousand feet depth. There's been nothing but small fishes so far," A male crewmate reported.
"Is there really hundred-foot big fishes down here like we were informed?" Another crewmate asked with doubt.
Intense beams of light illuminated the dark depths ahead of the sub while the captain observed on-screen.
"We will find out soon enough," The captain stated calmly.
Only a few moments passed before a female crewmate alarmed, "Captain, we are picking up signals of a huge creature on the sonar!"
"Seems like we finally get to see what lurks the ocean depths," The captain muttered before barking, "Ready the torpedoes! If it shows the slightest sign of hostility, fire at once!"
"Yes, captain!" A few crewmates immediately hopped into their battle stations.
