Cave

You leave the pilot's seat and put on the pressure dive suit. Putting it on reminds you of the power loader from the Aliens movie. Except the suit is obviously air tight and there's no xenomorphs to face off against.

You walk out of the airlock and leave the Yellow Rocket behind. The suit's front mounted lights flicker to life and you head into the cave. The sub should just float in place while a long cord connects you back to it in order to guide your return.

It's naturally dark and your foot steps leave a trail of small clouds of dust. The cave appears to be very deep and more ominous than exploring the trench. A few more steps and you start to feel the walls closing in on you. Since you believe there's nothing here for you, you turn around and follow the cord back to the sub.

At least that was your hope. You see only a few feet of the cord in front of you. It appears as though the line was cut and now you're hopelessly lost in an underwater cave. At least it's not all bad. You panic and run forward in the hopes of finding the rest of the rest of the cord only to find what cut it in the first place.

A large eel with long pointy teeth looks at you with hungry eyes. It's jaws open to give you a view of your final resting place. It lunges forward and there's no escape...