We're also treated to Troughton in shirtsleeves inside the TARDIS, as he works out that they've landed inside a space museum. Two things are immediately apparent: 1) Troughton's shirt is really impressively baggy; 2) He has short sleeves by virtue of having hacked off the ends of the sleeves, rather than rolling them up or just having a short sleeve shirt.
But yes, there's trouble on the moon, and only one man can help before those troubles threaten the entire world (since food and medicine can't be T-Matted across the globe): the owner of that space museum, who's also the only person left on the planet with a working rocket. And while the controller of T-Mat, Commander Julian Radnor, tries to convince Professor Daniel Eldred, the museum/rocket owner, to help them, the audience learns that the moon has in fact been invaded by Ice Warriors!
Episode two is a little different in tone: the Ice Warriors are on the moon trying to cow the technicians there into fixing T-Mat for their own purposes, while the Doctor, Jamie, and Zoe are being readied to crew this rocket to the moon. It's interesting seeing the dynamic between Zoe, who's clearly familiar with space travel and all the experiences and risks it entails, and Jamie, who's clearly out of his depth but is determined not to be left behind. It makes for much more entertaining viewing, it must be said, than Jamie and Victoria's interactions ever were.
But episode two is about preparing for this journey into space and then what that flight will entail; remember, this went out in early 1969, so audiences were used to news stories and shows about this anticipation and what space travel would realistically be like. Obviously we're in the future, so some of the verisimilitude has been sacrificed in favor of ease ("Switching to automatic gravity control now," Zoe says so that they don't have to simulate weightlessness), but there's still a gesture toward doing things properly. Of course, we also get the wonderful pop-art sequence at mission control in preparation for lift-off, with everything initially viewed through a circular cutout, and then as Miss Kelly does the countdown the numbers are illuminated on her face in reverse. It's quite striking -- no wonder it's a clip that tends to get a lot of use in Doctor Who retrospectives and the like.
But disaster strikes, and the rocket loses their homing signal to the moon -- which means there's a real danger that they'll drift off into eternity forever. And more importantly: it's been two episodes and we still have no idea what the name of the serial means. Just what are the seeds of death?