East of the sleeping people is a dark room with a strangely visible light switch. It seemed too obvious to just hit the light switch, so do the very slightly less obvious thing and use your Night Vision.

Aha! More sleeping guards! Good thing you didn't turn on that light! Hey... wait a minute. That means those people outside were sleeping with the lights on! What the fuck?

Head north to find a room with a hospital cross on it. Hooray! An infirmary! I bet this will be stocked with...

What the-? The Zanzibar Infirmary is just an empty room with a bottle of pills in it!

And the pills aren't even marked! What a ghetto ass infirmary! No wonder they didn't even bother giving me a gun on this mission!

On the south side of the hallway of sleeping people is... a sauna! Wait a minute! Why did the graphic artists spend time making this room look like a sauna, but somebody else said, "That infirmary just looks like a closet? Good enough. ARE YOU PEOPLE DONE DRAWING THE UNREADABLE WARNING SIGN IN THAT SAUNA? DETAIL, PEOPLE!"

Yikes! A naked solider comes in! The censorship black circle hovers around his midsection, strangely implying he has hovering, detached genitals.

In Metal Gear Solid 2, by the way, your main character had to go through a portion of the game naked (He was covering himself with one hand, but I didn't find it particularly pleasant to see so much video character ass in one sitting.) Now, two games earlier, we have a scenario where an enemy soldier walks naked through a dark hallway of sleeping men to get a steam bath.

Draw your own conclusions.

Compare these two inventory screens. The steam from the sauna changes the "ZL" shaped brooch into... a key?! What the fuck is this? King's Quest? How can steam change that brooch into a key???

That key, opens this locker, and you'll find...

A cassette! By the way, this locker's a shitload bigger on the inside, huh?