Experimentation.

Simon woke up to the sound of a dripping tap lying on a metal table feeling freezing cold.

The only light in the room came from a green exit sign above the door.

He lowered his legs over the side of the table feeling stiff and sore.

He winced when his bare feet hit the freezing cold concrete floor.

Feeling slightly dizzy he made his way to the door.

He pulled it open and stepped out into a shop.

He spotted an old man staring at him from behind the counter.

He said in a voice that was not his own where am I?

The old man stepped from behind the counter saying as he did so it's ok my dear just go back to my workshop and I will explain everything to you later.

Simon still in a state of confusion did what he was told.

He made his way back into the workshop and sat down in an old leather chair & covered himself with a blanket.

He dozed off as he waited for the old man to come and talk to him.

Sometime later the old man enter the room with a tray of sandwiches and a glass of milk and some clothes for him to wear.

The old man explained to him as he devoured his sandwiches this was the only way to save his life.

He explained to him that he had come across a car wreck on the side of the road.

He managed to pull him out but his body was crushed beyond repair.

But luckily for him he was a retired / disgraced Russian scientist who had a way of saving his life which came with a few complications he did not expect.

IE: turning you into a  fully functioning female version of himself.