The complexity and depth of Metal Gear's fictional history and lore rivals that of any RPG worth its salt, and as a result many of you may have had no idea what happened in the Metal Gear Solid: Ground Zeroes trailer that dropped a few hours ago, especially if your history with Metal Gear never extended to the PSP.

Luckily for you, the Joystiq Qrew has spent over four hundred trillion collective hours immersed in the murky waters of Metal Gear, so we're going to lay down what the eff just happened as best we can. Needless to say, things could get a bit spoilersy, so all the goodies have been tucked away after the break.