Nightmare Fuel / When Worlds Collide

• The "Last Dawn" with Bellus filling half the visible sky, dwarfing the tail of the Ark. Even with 70 year old special effects, the Red Sky, Take Warning and rumble of approaching doom are creepy as hell, all dominated by the enormous Bellus. Further hammered home when, while testing the Ark's camera systems, Randall happens upon a view of Bellus filling focal arc of the camera.
• The titular collision between worlds. In its final moments, Earth becomes a molten ball of flame as Bellus makes its final approach, then finally explodes.