So the whole story is that people from another world infect our plastic so they might be able to come up with a cure for their own people. I'm a pretty good environmentalist . I think we are killing our planet and those people who think the world is not warming are complete idiots. With that being said, I don't want my favorite television show to smack me right in the face with it. Now, people will say "Well, Dr Who has always been show about activism" and that is partially true. The difference is that the show used to bring up social issues with a more subtle approach. Not being slammed right in the face with it. Even if you agree with the message (like I do), it's a total turnoff.
I can't even think of anything positive about this episode. The story doesn't make a lick of sense. The companions don't have much to do. Jodie Whittaker is still lousy. I guess the only positive from this episode was that it was not a two-part episode.
I'm keeping this short, because I never want to relive this episode again. I will give "Praxeus" a 0.5 Tardises out of 5. We can only go up from here.