Samus would see nothing in the water.
[hr]
Shinagawa Ward, Tokyo. 7:22AM
A pair of merfolk, one tall and muscular, the other shorter and lithe, emerged from the water, followed by five others. They began making their way down side streets, keeping out of sight as much as possible. They encountered a few humans, but the larger merman simply decapitated them with his broadaxe.
After a few minutes, they arrived at a fairly large building, which they had scouted earlier in the night. Since then, it had filled up with a number of people. The seven merfolk quickly charged in, taking everyone by surprise.