"He chose to stay, to look after mum." Tori Johnson's final act was one of profound compassion.

When Louisa Hope walked into Martin Place’s Lindt Cafe on December 15, 2014, her life changed forever.

Louisa is one of the Sydney Siege survivors. She and her then 72-year-old mother Robyn Hope were held at gunpoint and trapped for 17 hours before the gunman executed cafe manager Tori Johnston on his knees in front of her. Another hostage, Katrina Dawson, was killed moments later in gunfire when police stormed the cafe.

In 2019, five years on, Louisa told Mamamia's No Filter podcast of Tori’s final moments, and his act of completely selfless compassion.

You can listen to Louisa’s full conversation with Mia here. Post continues below video.

They were already hours into the 17-hour siege, when after a bathroom break, Tori returned to the shop floor and sat himself next to Robyn, who had been losing patience with the gunman.

“Where he positioned himself next to mum, I could hear them just quietly whispering, having little jokes, I could hear little giggles and when I had gone on a bathroom break myself and come back, I could see them holding hands under the table,” Louisa told Mia Freedman on No Filter. 

“So Tori had used that as an opportunity to position himself next to my mother to calm her and I could see that that worked, because mum was far better.

“There was one stage when the gunman said to me ‘Louisa, keep your mother quiet’ and in the moment I thought ‘You’re crazy, how am I going to that?’… Here I am, a grown up, but I had that moment where I had to say to mum, ‘Mum, you’re an old lady, just keep quiet’ and I could see her looking at me, like ‘Wait till we get home, you’re in big trouble’ kind of thing. But I knew we just had to keep her calm, and Tori obviously read that too.”

At 1.43am on December 16, Tori texted his family that the gunman, Man Haron Monis, was becoming increasingly agitated and wanted to release one hostage in good faith.

Just 20 minutes later, six hostages fled the building as Monis shot at them. It was at this point that Louisa recalled running towards the exit, only to look back and see Tori and her mother staying put.

"I stood up and I started to go towards the door but Mum and Tori were not moving," she said.

"I was trying to catch their eye, I kept turning around, not wanting to speak because I didn't know where the gunman was, I didn't know what was happening to him. I was trying to indicate to them 'Come, come', we're right at the end now and I'm trying to get their attention but they weren't moving.

"I'm thinking 'Why isn't Tori moving? Why isn't mum moving? They're just not shifting'. In that moment, I just thought I can't leave my mother so I laid down on the floor and thought the gunman will kill me."

It was only 12 months later, after the first anniversary of the siege, that Robyn explained why they hadn't moved.

"Mum and I were having a quiet moment at home and I said 'Mum, do you remember at the end I'd got up and was going towards the door, why didn't you and Tori run?' because I could never understand why Tori didn't run. And my mum said to me, 'Oh, well I was saying to Tori, you go, you go,' and she was making this motion like she was elbowing him in the side saying 'You go Tori, you go' and he said to her 'No, I'll stay, I'll stay with you'.

"So in that moment, 12 months after the event, I suddenly realised that Tori Johnson had made a deliberate choice to stay, to stay and look after my mother."

Louisa said that for her whole family, the act was "profound".

At 2.14am, the gunman shot and killed 34-year-old Tori.

"I understand the grief that his family must feel that his brave heart made that choice in that moment, because if he had not, he would not have been there to be the one that was killed.

"It's hard and I feel for his family, but I think to myself what an amazing, brave young man. His parents, his mother and his partner Thomas [Zinn] - his bravery doesn't replace him for them but our family, we are forever grateful because in lots of ways that gave us three and a half more years with our mother. It's in my heart."

A police sniper witnessed Tori's death, and reported a hostage down. Police stormed the cafe, throwing 11 stun grenades and shooting Monis. Officers fired multiple rounds: barrister Katrina Dawson, 38, was hit by stray bullets and died.

Louisa and Robyn were among three hostages injured by the police fire: Marcia Mikhael was shot in the leg, Robyn was shot in the shoulder and Louisa was shot in the foot.

She spent three months in hospital following the siege. Though she never expected to be in so long, with hindsight Louisa believed it was the best place for her - obviously physically, but also mentally.

"You don't think about it at the moment, but in hindsight I realised it was a blessing because it insulated me from the world immediately after the siege. It gave me time to reflection and to think forward," she said.

She was so moved by the care and compassion she received there, she decided to create the Louisa Hope Fund for Nurses as part of the Prince of Wales Hospital Foundation, which has so far raised $360,000 to fund equipment, research and care initiatives.

"A nurse once said to me, about a week and a half into my stay at the hospital, she said 'Even though I was on morning shift, I had to stay up to the very end and watch on the television. I couldn't leave you alone'.

"We recognise this as something that happened to all of us. When you think about what happened in Martin Place after: I was in hospital and on a self-imposed media blackout but friends were bringing me news and telling me stories and photographs... They're telling me about random strangers talking and praying and Muslim people being there, and everyone sharing together.

"All of that stuff, I think it very clearly made it obvious that we were all in this together."