Keep walking down the corridor

You back away from the strange young man and turn to continue on your way, but something strange begins to happen. The water feels...thicker, somehow, each step growing harder to take, until it feels like you are slogging through wet cement. Gasping, you stop and lean against the wall to catch your breath.

"Nice night for a swim, eh?" the young man asks as he swims past you, appearing to have no trouble with the water. You attempt to take another step, and it feels like your legs are encased in stone.

"It is night?" you ask, watching him glide lazily through the uncooperative water.

He shrugs. "Beats me. I haven't been out of this dungeon in a couple of weeks."

"Are you a prisoner, too?"

"Not exactly," he says, giving you a small, playful smile. "My name's Tide, by the way. Do you want to swim with me?"

"I seem to be having a little trouble with this water," you say, heaving your body to the side to try to free one of your legs, but it doesn't budge.

Tide giggles. "I could help you with that, if you promise to help me with something."

"Help you with what?"

"It's so boring in this place, swimming back and forth through the corridors all day, waiting for some hapless adventurer to stumble in," Tide says. "I want to have some fun - some hot and heavy, down and dirty, making waves kind of fun."