So, how will Jo escape the giant maggot crawling up behind her when she is alone in a dark room?
Well, simple: she doesn’t have to. Some doofus working for Stevens sneaks in from a side door to steal the egg the Doctor recovered, and the maggot bites him before it can slither away. Jo screams (of course she does), causing the rest of the house to come running in to find the downed doofus and a trail of slime leading outside. Now, it does turn out Professor Jones discovers the maggot’s cells tend to assimilate human cells, and that would be what the Green Death is. That means Jones can look for a cure, and it would help if he had a sample of the chemicals from Global Chemicals that are maybe making the maggots so darn big.
Good news there, everyone! UNIT is here and the Brigadier has a plan.
Bad news, everyone! His superiors ordered him to blow up the mines to try and seal the maggots underground.
Now, simply blowing things up is never the Doctor’s favorite plan, so he complains to the Brigadier. But, the Brigadier says his hands are tied, so the Doctor should go complain to Stevens. Complaining to Stevens doesn’t do much good, as Stevens just directs him to some new guy who the government sent over…a guy named Yates.
Yes, as the Brigadier points out later, despite what some alien time travelers would like to believe, the Brigadier isn’t stupid. He has orders, but he can still slip an undercover Captain Yates into Global Chemical to find out what’s what. At first, Yates can’t say much since there’s a security guy watching him in his own office, But the Doctor has a plan to get a sample of the chemical waste if Yates can help from the inside (he can).
Besides, the Brigadier figures that’s the last we’ll see of the maggots (cue comical music as no one believes that save the Brigadier).
Are the maggots dead? Nope! They just dug themselves through the dirt to the surface. Because of their chitinous hides (and being they are on Doctor Who), they are also, of course, bulletproof.
Still, the Brigadier can try an air attack later since the maggots are largely confined to one field.
But the Doctor still needs his sample, so he leaves. His excursion occurs as Jo and Jones get closer. Romantically speaking, that is. But Jo is still clumsy, and she knocks Jones’ mushroom sample over the maggot slime. Jones isn’t happy about this and basically tells Jo to go away while he works. Jo, feeling bad, decides to collect a maggot for study and slips off while Jones is distracted.
Jo is going to that field the Brigadier is about the bomb, isn’t she? And does she really think a wicker basket can hold one of those maggots?
But where’s the Doctor? Well, he stuck on a fake mustache to disguise himself as an older milkman to sneak into Global Chemical, and then once inside switched to a cleaning lady’s outfit, allowing Jon Pertwee to do some broader comedy for a change. Yates gives out some valuable intel: Stevens isn’t in charge. He has a boss on a different floor. And when the Doctor goes there alone, he meets Stevens’ boss. His name is BOSS. He’s a computer.
Of course he is.