The planet seemed nice enough. Not that we would've had much choice if it wasn't. Colony ships aren't exactly equipped to turn around and go home. All that would cut into our already tightly managed mass allotment. Refuel in situ and build some propulsion lasers to send it back.
Some of our first exploration teams saw some life forms. Nothing responded, we were probably the only intelligent species for six parsecs in any direction. For that matter, the plant life seemed a bit more dangerous. Some of its apparently carnivorous and big enough to trap something human sized. Just because it doesn't eat you, don't think you can't eat it - a great deal of the stuff contains a variety of toxins - we've even found stuff containing nerotoxins like tabun. That stuff can kill you with micrograms.
Then they took a look at a few of the more interesting geological formations. That was a find - not geological at all. Cities. Partially buried, mostly overgrown, and long abandoned. A concern, bit hardly a problem.
Our troubles really began when the effort shifted into high gear. One of the shuttles crashed. So naturally - we set out to recover, investigate, and pay respects to our friends. Much to our surprise, they came out to greet us - mangled, burned, and hungry.
Someone overworked them-self - heart attack. Colony control noticed, and dispatched a medical team to recover the body. By the time they arrived, the worker was up and about again.
It seems we have set ourselves up on a planet where noting just stays dead. One with underground cities, jungles full of unknown predators, and hazardous plants.
We have neither the propulsion array or the pettawatts of power needed to leave, or even launch a message drone. It'll be years until another ship is scheduled to come this way. We're on our own with nothing but wits and fire.
The surface is getting too hostile. We're heading to the underground cities. Hopefully there will be clues there.
Whoever finds this - get out while you still can.