Nazy was on her way to buy a book in Tehran's downtown Enqelab Street and planned to attend a demonstration that afternoon at 4.
At noon, Nazy had just climbed out of the car in front of the bookshop when a man in a white vest, blue shirt and white sneakers twisted her arm and slapped handcuffs on her.
Nazy saw five or six men beaten as they were led into the detention center.
Nazy herself was hit a couple of times on her back, led into a basement and interrogated.
Another guard came in and challenged Nazy for being a member of the 'One Million Signature' campaign -- a group pressing for changes in Iran's laws on women.
Nazy and two other women waited for several hours in a van while more female demonstrators were brought in.
Nazy slightly lifted her blindfold and watched guards hit around 60 men -- mostly young -- in the head with batons.
In the morning, Nazy wore a chador, was handcuffed and blindfolded and walked with a guard to an interrogation center known as the Evin School -- so called perhaps because of the school desks used there.