Linda's rescue

Confronting Mistyra
After returning to the Science Lab Tower, Lust Doll would learn that Linda never made it back, and the infestation never dissipated. The only option that remains is to return to the Deserted Base and confront Mistyra about this.

When pressed, Mistyra reveals that Linda was taken to the lower levels of the base, where the infestation is much worse than towards the surface. She agrees to take Lust Doll there, if they are willing to risk. But they are gonna squeeze through a small meat... tunnel, which wouldn't be easy.

When you're ready, talk to Mistyra. Be warned that, upon starting the quest, you wouldn't be able to return until it's finished.

Unlikely partners
The quest proper starts once you squeeze through the tunnel, ending up in the Meat Parasite Nest. It requires either passing a Nimble check, indulge yourself (and the live walls), or ask Mistyra, with subsequent scene(s) (and the lust you would end up with) depending on the options picked. Regardless of the picked options, you're gonna be slimed.

However, once they squeeze through, lust Doll would learn that Mistyra has took their clothes, and is not gonna give it back!

Mistyra is willing to proceed further, but wouldn't provide any support if you get attacked – and you would, as the depths are infested with various lusty monsters.

Soon, you would run into some kind of meat barrier, which may only be removed by finding corresponding meat orbs and deactivating them. Some orbs are seemingly out in the open, while the others (those responsible for blocking the main exit) are hidden in the side rooms which may only be accessed by either having high enough Senses, or running into them blindly. Mistyra is willing to deactivate one orb, but would refuse to help with the rest. From now on, the path which may be taken is linear, as nearly all entrances are sealed.

Discovering the way out
At some point, Mistyra would refuse to go further (not that she was of much help anyway). This is when you would discover Linda. Linda would be trapped by Meat Tentacles. You may choose to help (which would initiate the battle), or wait and watch. Choosing to help at any point initiates the battle against Meat Tentacles, which can't be run from, and leads to unique scene if lost. Choosing to wait leads to Linda being molested, and skips the battle.

Regardless of how the things went, Linda would join you as a companion, providing some aid. Linda would discover that she now has some weird connection to the Parasites, and would be able to operate the orbs on her own. But each activation makes her progressively more dizzy. After activating enough orbs to unlock the exit, Linda would shamble somewhere. As the exit is sealed by the final orb, which only Linda can deactivate, you have no other option than to go search for her.

Linda would be found standing near the edge of abyss in one of the side caves. When approached, she would suggest you to look down. Regardless of wether you fall for that or not, she would try to push you down. If you fail initial Strength check, you would fall into the meat mass below, and have to pass the series of Strength checks to go back. Failing any of them, or deliberately choosing to succumb would result in them grabbing you back, and immediate game over.

If you survive, you can find Linda near the final orb on the north, behind previously sealed entrance. When approached, she would reveal herself being covered by meat parasites, giving her form and abilities similar to Mistyra's. She would immediately attack, leading to a boss battle; losing it also leads to game over.

If you survive the battle, Linda would come back to her senses, though you would have an option to molest her a little further, and even fuck her if you want to (and have a dick). On the exit, Mistyra would reveal that she knew about this all along, but chose to wait and see, because why not. At least, she's willing to return your clothes back.

Linda is saved... but there's still no way to deal with the meat parasites attached to her body.