Classified Intel Acquisition

Classified Intel Acquisition was an operation that was undertaken by the private military group Militaires Sans Frontières regarding classified intel that had been retrieved by a mole at a prison facility in Cuba, Brian.

Prelude
The mysterious Cipher-backed XOF ended up working at the prison facility in Cuba, allegedly as CIA agents. Their leader, a scarred man known only as Skull Face, proceeded to torture heavily one of the prisoners, also relaying to the suffering prisoner his past and his motives before telling him in vain not to die.

Brian ended up witnessing this and recorded the data on a cassette tape and encrypting it for analysis for his superiors.

Intel Acquisition
On December 21, 1974, at 18:08, Big Boss, the leader of MSF, personally infiltrated the base by stowing away on the back of a truck, noting the presence of several armed guards before locating Brian. However, because of the security being heightened to the extent that casual conversation would have risked blowing Brian's cover, Big Boss instead placed Brian in a chokehold and "interrogated" him so the latter could relay the tape or at least its location without drawing suspicion. Brian admitted that he doesn't have the tape on him, but assures him its close by and safe. He also attempted to warn Big Boss about XOF and Skull Face, but decided against it before telling Big Boss to put him in a sleeper-hold to ensure his cover remained intact. Big Boss deduced the specific location of the tape and proceeded to escape.

Aftermath
Afterwards, MSF decrypted the tape and became aware of Skull Face's existence. The tape, depicting his brutal interrogation of a prisoner, acted as proof that the base became a black site, although despite the intel, it did not come with a full plan. The tape, that was obtained in the control tower, was in fact a trap. Presumably, Brian and the other Pentagon agents ended up silenced in the aftermath by the base personnel.

Behind the scenes
The mission first appeared in the TGS 2013 daytime demo for Metal Gear Solid V: Ground Zeroes, although the date was given as the day the demo was issued. The player could either escape via chopper or, if that fails, escape via a stolen jeep.