The Geek Secret is a superiourly hidden secret in The First Encounter only in the Sacred Yards level. Essentially it is a very complex speedrun secret that will let you fight absolutely no enemies (Seriously? A Sam thing that requires not to kill anything? How ironically absurd) and get to finish the level quick. If you do not know how to access the secret level, as soon as you're at the ending of Luxor, take a sharp left as soon as you enter the end level's giant double doors after collecting all four ankhs. There will be a set of smaller double doors that'll directly lead you to the Sacred Yards.
This secret can be accessable with all Sam games, be it Classic, Revolution, HD, VR and even Fusion.

As mentioned, this secret is complex and not to mention very touchy. Strictly follow the steps and you may not get a sudden surprise attack you weren't prepared for. Do not try touching any other set of items or blow any other objects up to prevent jeopardizing the secret. Also at it is a speedrun secret, this is timed and you will have to do it quickly before it disables itself and returns the enemies.

As soon as you start the level, immediately turn to your right and grab the Silent-walk Pill. You have about three seconds to grab it before it disables itself and becomes the Not So Silent-walk Pill. Nabbing the Silent-walk pill will give you the message, "Silent-walk pill has been activated and enemies deactivated!" This means enemies will not normall spawn anymore and the trigger for the Geek Secret has begun. If you were too slow and got the Not So Silent-walk Pill, you will be greeted with a Biomechanoid Major and expect a Not So Friendly rocket (or two) to the face as well as the rest of the enemies will spawn normally.
http://sp.zhabite.com/sharedfiles/filedetails/?id=893610772
The start of the level
http://sp.zhabite.com/sharedfiles/filedetails/?id=893610807
Turning right to see the Silent-walk Pill #1
http://sp.zhabite.com/sharedfiles/filedetails/?id=893610835
The Silent-walk Pill successfully being activated

After you grab your first pill, walk all the way to the back of the path and turn to the farthest tree on the right. Swing your Knife at it or explode it with a Rocket Launcher to spawn a pill tucked away in the left corner of the exit doors. You will hear a distant explosion sound that has destroyed the cental pillar in the upcoming first pool room.
http://sp.zhabite.com/sharedfiles/filedetails/?id=893610883
The tree
http://sp.zhabite.com/sharedfiles/filedetails/?id=893610921
Pill #2

Turn around and pull out your Rocket Launcher (if you haven't already) and blow up the statue that's over the fountain. This will automatically open the exit doors and you have to sprint inside before the door closes and the secret disables itself. Quickly grab the pill inside the tiny hallway or else you will be swarmed with Marsh Hoppers and invisible Gnaars.
http://sp.zhabite.com/sharedfiles/filedetails/?id=893610960
Blowing up the statue
http://sp.zhabite.com/sharedfiles/filedetails/?id=893610989
Exit door open
http://sp.zhabite.com/sharedfiles/filedetails/?id=893611038
Pill #3

After grabbing the 3rd pill and going through the door, you will be in the first pool room. Grab the 4th Pill in front of you (this pill used to be the one that spawned Pinky, the miniature common Reptiloid) and walk up to the central platform (where there used to be the aforemention destroyed pillar). The 4th pill will activate the secret Geek teleport that'll automatically teleport you to the Sphinx room.
http://sp.zhabite.com/sharedfiles/filedetails/?id=893611078
Pill #4
http://sp.zhabite.com/sharedfiles/filedetails/?id=893611135
The Geek teleport

In the Sphinx room, with your Rocket Launcher still, blow up the statue in the center in the room and the giant doors which were previously locked will open its left door up to you. As you get closer, the right side will open as well.
http://sp.zhabite.com/sharedfiles/filedetails/?id=893611162
Shooting another statue
http://sp.zhabite.com/sharedfiles/filedetails/?id=893611190
The door opening

After exiting the Sphinx room, immediately turn left and go along the wall to find your 5th pill and grab it.
http://sp.zhabite.com/sharedfiles/filedetails/?id=893611233
Pill #5

After grabbing the 5th pill, enter the door on the left to collect the first gold Sphinx. As soon as you enter the room and see the central platform start to rise, immediately shoot it with a rocket launcher and if it succeeds, the platform will explode and you'll achieve the first gold Sphinx without a sweat. If you let the platform get all the way to the top, it will become indestructable and you will have failed.
http://sp.zhabite.com/sharedfiles/filedetails/?id=893611266
Entering the first Sphinx room
http://sp.zhabite.com/sharedfiles/filedetails/?id=893611314
Retrieving the Sphinx from the rubble

Having retrieved the first Sphinx now, immediately turn around and leave the room the same way you got in. Path your way down to the center and walk behind and past the center Sphinx statue. Do NOT blow this up.
http://sp.zhabite.com/sharedfiles/filedetails/?id=893611362
Walking past the statue

Enter the next room where the second pool is. Avoid trying to get the sphinx first and hurry yourself toward the Serious Pack on the left side. This is on a timer too as soon as you enter the room, so try to get it as fast as you can. The best approach is to come from the left of the Pack as it will float itself leftwards when you draw near it. Collecting the Pack correctly will just have Sam say, "Hah!" and nothing else. Doing it incorrectly will have him saying it, plus the walls closing on you and pit you against a Biomech Major blowing down the opposite wall and you will be pushed and trapped in the secret pyramid area.
http://sp.zhabite.com/sharedfiles/filedetails/?id=893611391
Turning left to see the Serious Pack

If you've collected the Pack correctly, return to the pool area and now try getting the 2nd gold Sphinx. Do NOT step on the pressure plate as it will rotate the platform in the center of the pool. Instead, avoid it and go to said platform. Usually to do this, you would need to push the button to flood the pool with more water. Ignore pushing the button and instead use it as a stair by jumping on top of it and climb yourself to the upper window leading directly to the Sphinx.
http://sp.zhabite.com/sharedfiles/filedetails/?id=893611483
The pool's central platform
http://sp.zhabite.com/sharedfiles/filedetails/?id=893611520
Easily getting Sphinx #2

Once you get it, it's just a straight shot to the level's exit back in the main room with the Sphinx statue. Jump down into the water and climb up the stairs to go back where you came from (ignoring the secret platform enabled after getting the Sphinx). Place yourself in front of the statue this time and you'll be done with the level and have successfully done the Geek secret without killing a single enemy. Congrats!

http://sp.zhabite.com/sharedfiles/filedetails/?id=893611564
The end

If any of this does not help, there is a video on YouTube made by SolaisYosei that explains it all.
https://www.youtube.com/watch?v=gHUGellS55w

Be sure to check out my other secret guides for the main games as well for First & Second Encounters, Sam 2, and BFE!

http://sp.zhabite.com/sharedfiles/filedetails/?id=231547960
http://sp.zhabite.com/sharedfiles/filedetails/?id=121303955
http://sp.zhabite.com/sharedfiles/filedetails/?id=127960413
http://sp.zhabite.com/sharedfiles/filedetails/?id=481397482
http://sp.zhabite.com/sharedfiles/filedetails/?id=129738470