Atlantis8

You send out a probe with a video camera. Once it gets behind you, you can see everything without becoming vulnerable! You think you see some sharp teeth, but you disregard it. As the proobe goes farther and farther back, you begin to see something move. It's a door opening! What could it mean? Will you...
forget about it and investigate the teeth,
enter the door,
send the probe through the door,
or,
try to escape the cave without the door?