First of all, no, I'm not mistaken, it's not that Base Moon add-on for MZC mod, heh.
This version of Alien Base Moon was created and uploaded by lambsiburtouk on one Russian website back in 2015. I always try to check all permissions and talk with any author, but this time I couldn't contact original creator to find out about permissions since he was AFK for several years.
So, I will delete this translated version upon message from him, if he decide to request it.
Well, let's get started.

WHAT TO EXPECT
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1) New dungeon/arena type add-on for Mothership Zeta Crew mod;

2) Several new exteriors and interiors on Moon (Underground City of Zetans, Camps and Lab included);

3) More Zetans to shoot, more loot to take, more Alien Wormfood to eat;

4) Around 15-20 minutes to see all new content;

HOW TO INSTALL
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Of course, you will need Mothership Zeta DLC and Mothership Zeta Crew mod for this addon.

1) Place the .esp in the Data directory of the game 
2) Activate the alienBasemoon ESP file and run the game.
OR
1) Just use Vortex installation path and activate plugin.

HOW TO START
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You need to find separate ship to the Moon in Main Hangars (see "Images" section for more details). 
Before entering "Door to Moon", take Thunderfist Captain Armor/Helmet from container near this ship. Without it you won't pass the door.

Don't forget your best weapon.

BUGS AND CONFLICTS 
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I can't provide information about compatibility with every MZC add-on, but it WON'T conflict with, already mentioned, Mothership Zeta Crew - Moon Base mod.
So you can use them together. But if you find any conflict with other TSC addons - don't hesitate to report them in comment section.

CREDITS
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My deepest gratitude to  lambsiburtouk for creating this dungeon mod for MZC.
All rights and praises only to original modder. Original Mod Page 
Again, I will immediately remove this file if lambsiburtouk will contact me about this issue.
Also big thanks to OnyxSix for TSC Clean Logos, great for wallpapers and other stuff.