C539 Dive into the Dark Abyss(2)

"So quiet. What's the engine of this thing? Why is there no sound?" Percivale asked curiously.

Tristan ignored Percivale. The structure of the submersible vehicle was a military secret of the Merman Race.

Seeing that Tristan did not say anything, Merlin could not help but to say: "I'm afraid there is no engine, the entire ship is controlled by runes. After receiving the command