Corinne Rey had tears in her eyes but her voice was clear as she gave evidence at the trial of 13 men and one woman accused of helping three men plot the attacks on January 7-9 2015 in Paris.
Seventeen people, including 12 in and around Charlie Hebdo’s offices, four at a kosher supermarket and a policewoman, were killed.
All three attackers were killed in subsequent police raids.
This is something I will live with the rest of my life. I felt so powerless, felt so guilty
Ms Rey had left the weekly editorial meeting a little early to go downstairs for a cigarette when the gunmen came in the door, calling her by her pen name Coco, and ordering her to take them to the Charlie Hebdo offices.
She walked upstairs between the two men armed with assault rifles.
Only at the moment when Ms Rey described leading them accidentally to the wrong floor of the building did she falter, crouching down and holding her arms over her head in a replay of her reaction as the gunmen realised her mistake.
Said and Cherif Kouachi targeted Charlie Hebdo because they believed the newspaper blasphemed Islam by publishing caricatures of the Prophet Mohammed.
They opened fire on the group seated around the offices as soon as they entered, but told Ms Rey they were sparing her life as a woman.
“This is something I will live with the rest of my life. I felt so powerless, felt so guilty,” she said.
Now, she said: “I expect justice to be done here. It is the law of men that rules, and not the law of God, as the terrorists would have it.”
On the day the trial opened last week, Charlie Hebdo reprinted the caricatures.