Once he stopped, he felt a hand slide onto his own shaking one. He squeezed it right back, a silent thanks. Just a day ago, he thought Shiro would harm him. Eat him, even, if he could. But soon he found that he was a protector of sorts to him. Even if some of the dormant alarms in his mind still blared in warning, he was still in the water, not planning on leaving it.

So, he ventured deeper in, his breath catching in his throat as the water began to creep up farther and almost close to his chest. It was either so cold or Keith was frightened for his life at this point, but soon he was chest deep. His heart thumped and dropped down to his stomach in fear, only to rise up again as he moved around, careful not to drift away too far. Away from Shiro. 

"Heh.. fuck, I'm actually-" he almost said before he stopped. His legs felt strange, wobbly, like they were numb of feeling but still moving in unison underneath him. Keith couldn't see anything underneath him, or maybe he was too anxious to look. It was like his legs were being brought together by some force, melding into each other, and while it felt ticklish at the beginning now it just hurt. He retracted quickly, swimming back to the beach, breathing all over the place as he returned to the yellow shade of the shore, collapsing on the ground away from the water. 

"What the fuck was that?!" He yelled out in fear at his legs, pulling them up to him and looking. They were normal. Wet, understandably, and normal still. His mind was playing tricks on him, and he was shaking, staring in confusion at the merman.