As you pause to consider (and to enjoy the horrified expression on his face), you feel something close over your tailfin and pull you back into the water, breaking the spell along with your concentration. You turn to see several frogmen, two of whom haven't let go of your tail, and two more who are already moving to grab your arms and cover your mouth.
Soon they have you under control, and despite your thrashing they manage to pull you out of the water. The man is staring, shocked at the appearance of even more strange creatures and (you are gratified to notice) still distracted by your figure.
You think you recognize the frogs' leader as the one who recruited you as a spy. Sure enough, he turns to you and says, "Don't be so surprised. We've been keeping an eye on you since you left. I had my doubts, and it looks like I was right." He turns to the man. "These mermaids kidnap men from land, and if they refuse they're turned into creatures like us, or worse. You're lucky we were here to stop her. She was a spy, but she double-crossed us and joined them for real."
He looks at you. "But now that they trust you, we can replace you with someone trustworthy. All we have to do is make sure you stay out of trouble."