Amoebic disturbance

You go for a deep dive one early evening in the waters off the coast where you live. After diving down into the deeper parts of the water, you suddenly get this peculiar feeling in your mind. Something attracts your attention that you've never seen or heard about before. You see a wild morphing glowing mass gliding closer and closer to you. It's strangely alluring and instantly captures your full attention. You try to swim away but you're frozen by the mere sight of it. You better swim away now and fast!