I am at the point when we are told the Aliens are going to be here in 400 years time. The Aliens through some clever tech have sent something to Earth look over us and disrupt our technological weapons development. So when the baddies do finally arrive they will be safe in the knowledge that they will be able to destroy humanity with superior weapons.
The humans appear to have overlooked the fact that we are unlikely to survive as a species for anymore than another 100 years after making the planet inhabitable to most living things.
I would highly recommend the current humans in communication with the baddy aliens should either deter them for coming to Earth as it will be rubbish in the year 2424 or to get them to send us some up to date tech to combat the effects of global warming and avoid the 6th Mass Extinction.
At present it’s lose/lose for both parties and this hasn’t been discussed. It’s a hot topic on Earth at present (no pun intended).
Personally if I was told we are all going to die in 400yrs by an Alien species I wouldn’t be concerned. Our biggest threat to life on Earth is currently Humans, and well before then.