after being arrested, sent to prison, and taken by the foundation to be a disposable test subject. One day, your pulled from your cell and taken to a part of the facility devoid of male personel

Male guard: "you'll be taken by other guards from here..."

you went to ask why, but two female guards grab you and take you. Eventually, you arrive at a containment area named, "SCP-166", inside, you see three female researchers

Dr. Lesly: "ah, the Class-D...right on time."