The beginning of sorrows

I started off loving this: the first couple of episodes were just brilliantly clever and although the kind of timescales aren't plausible for real three-body stellar systems, you can forgive them that. Then it just dropped the ball by introducing magic: how do the aliens talk to us? Oh, right, they have superluminal communications technology. Which is magic, not science, and if it did exist would mean they could send information into the past and thus solve the prediction problem they have. ...