God knows what happened.

Maybe some mad researcher was messing around, or some hostile group of interest was testing out their new anomalous weaponry, but it would seem that half of the sapient anomalies contained at Site-19 had turned into females.

Not only were they frustrated by this sudden transformation, but it was really distracting for personnel.

And just like that, SCP-173 was also transformed, which obviously was very bad.

Unfortunately for you, as you were watching your surroundings and trying to traverse the maze that is the Light Containment Zone, you began to hear strange noises, like the sound of something really fast scraping against the concrete floor.