Seeing the sonar screen return to calm, everyone in the cockpit heaved a huge sigh of relief. Whatever that thing was, it had at last disappeared.
No matter what was in the sea, they wanted to avoid it, especially in such a peculiar place.
"Turn on all the lights and keep moving forward," the propellers of the Unicorne stirred once more.
This time, with no other disturbances, Charles returned to the pitch-black abyss directly above the staircase they'd explored earlier. In fact, this abyss was at the back of the stairs that could be seen just by turning a corner, but they had completely missed it prior.
As the cabin filled with seawater, the submarine began to sink slowly into the vast pit.
Soon, the Unicorne arrived at the place where Charles's clothes had torn. He could even see room 15 filled with seawater, from which some scattered items slowly floated out.
The submarine continued to dive past door 15 and now officially entered the abyss below.
