I'm not sure exactly, but there are quite a few. It depends on how you define a story mission. Some side quests might also be considered part of the overall story.
MW2's campaign is purely fictional. The developers crafted an engaging storyline for the game, but it doesn't draw from real events. They focused on creating an exciting and immersive gaming experience rather than basing it on reality.
The number of MW pages equivalent to 1 novel page can vary widely. It could be anywhere from half a MW page to two or more, depending on formatting and content density.
There was a case where a woman entered a store she had visited many times. But this time, the layout was completely different in a way that defied logic. The aisles were in new places, and products were stocked in an entirely unrecognizable manner. It was like she had stepped into an alternate version of the store for a short while. This could potentially be seen as a glitch in the matrix.
Maybe there's a scientist character who is trying to study and understand the glitches in time. This character could be really smart and dedicated, using their knowledge to try and solve the mysteries related to the time glitches.