Its in the game. When mystera is following you in the lower meat nest (lowest point of base) lose an encounter and you can find a scene with them
after Linda gets taken from the science lab head to the base and mystera will be waiting for you and take you to the lower area after which as long as you don't go to the bottom left she will follow you and if I remember correctly you just have to lose an encounter in the lower to meat crawlers (perhaps tendrils) and you will get the scene!