"Parabolic" was a planned campaign mission in Call of Duty 4: Modern Warfare. Not even its true name is known. The reason the level is called "parabolic" is because of the only file currently available to the public that proves its existence, "parabolic.str". Most of the string file is missing; its contents only show hint strings and objectives. In the game's mod tools, parabolic's prefab folder's contents are nearly identical to that of Blackout's prefab folder, suggesting parabolic was an early version of Blackout. The intended skybox texture for parabolic (sky_parabolic) is also very similar to the skybox texture used for Blackout, further adding to the aforementioned theory. Furthermore, Blackout is the only mission in the game that makes use of BM-21 rockets; a debug string in parabol