Part 4Update 04:
Intro: YouTube DailyMotion
Mission: YouTube DailyMotion
Outro: YouTube DailyMotion
Some scientists are still kidnapped! Havoc is stuck on an island volcano and isn't allowed to leave until he can find out where Mobius, other Mobius, and Petrova are being taken.
We saw our first Tiberium refinery in this mission so why not talk about Tiberium?
Tiberium came to Earth in 1995. The first known impact site was in central Italy, near the Tiber river. Renegade shows us another meteorite in Peru. From sites like these, Tiberium spread like crazy, covering the planet and mutating plants and animals. By the 2070s, Tiberium covered most of the Earth and threatened to drive humanity to extinction. Dealing with the Tiberium problem is the main issue of the series. Each games' plot is driven by conflicts between different ways of perceiving Tiberium: As a menace or as a source of power.
What is Tiberium? Well, it's a thing. It appears to be a kind of alien life form that spreads through the ground, sucking up metals and other minerals in the soil. Then, green crystals form above ground, containing these minerals. In addition to the crystals, Tiberium releases radiation and lots of toxic and mutagenic gas. It's not fun to hang out in a Tiberium patch unless you're in a hazmat suit. Tiberium can evolve and does so: Blue variants form in time for Tiberian Sun, and a red version appears in Firestorm, the Tiberian Sun expansion. In Tiberium Wars, it is stated that Tiberium has gone from "crystal-forming parasite thing" to "crystals that turn whatever they touch into more crystals." A variation on the gray goo apocalypse but with green crystals instead. Or you could see it as Tiberium developing the Midas touch.
Why do harvesters exist? They exist because those sweet, sweet Tiberium crystals are easy money. They're full of minerals that would have been impossible to obtain using conventional mining methods. Consider rare earths, which have lots of industrial and medical uses and are essential to the production of many electronic devices. They're plentiful throughout the Earth's crust but rarely occur in high enough concentrations to justify the cost of setting up mining operations. Tiberium can concentrate minerals like those into crystals that you can just scoop off the ground with a glorified garbage truck. Not too shabby. Nod's war machine is powered by the minerals they extract from Tiberium. GDI, despite being a U.N. organization, also has to supplement its budget by refining Tiberium crystals. And then there are the Scrin... Let's not talk about the Scrin yet.