A civil servant armed himself with a narwhal tusk to tackle a murderous terrorist.
Footage released during the inquest into the deaths of Cambridge University graduates Jack Merritt, 25, and Saskia Jones, 23, shows a man rushing through a door carrying the long spear-like object.
The coroner’s court heard how civil servant Darryn Frost had grabbed the makeshift weapon when terrorist Usman Khan went on a knife frenzy.
The 38-year-old wielded the tusk while others used a decorative pike and a fire extinguisher to fight back, the inquest heard on Tuesday.
The Ministry of Justice worker later helped pin Khan to the ground before police shot him dead.
The court also heard from film-maker Amy Coop, who was in the Banqueting Hall to get footage of a feedback session.
She heard screaming and shouting and so went out on to a landing to see what was happening.
“There was more screaming and shouting and it very quickly became apparent that something very bad had happened,” Ms Coop told the jury.
“As soon as I stepped out on to the landing it was clear that something was going on.”
She saw Ms Jones lying injured on the stairs, with a man kneeling next to her trying to give first aid.
“She looked very, very unwell,” Ms Coop said.
“She was ashen, grey in the face. Her eyes were open and very glassy and staring straight upwards.”
The film-maker went to look for a first aid kit or something that might help stem the bleeding for anyone who was injured.
As she returned to the landing, she heard more shouting, including “a loud and guttural roar”.
She told the jury: “It was a horrible noise coming from someone. It sounded like the kind of thing you see in a film.”
Ms Coop passed civil servant Mr Frost on the stairs as he carried a narwhal tusk which would later be used to chase the killer, the inquest heard.
Khan, 28, who was armed with two knives and wore a fake suicide vest, was tackled by members of the public with a decorative pike, narwhal tusk and fire extinguisher, and was then shot dead by police on London Bridge.
Earlier, jurors were shown graphic footage of Khan lying on London Bridge after he had been shot for the first time.
The 28-year-old could be seen rolling around, removing his jacket and gloves, while officers kept members of the public back.
Around eight minutes after he was first shot, he sat up, prompting police to shoot him again.
Less than two minutes after the second shots, he stopped moving.
Barrister Catherine Jaquiss, who shared a table with Khan at the Learning Together anniversary event, described how Khan seemed before he killed Mr Merritt and Ms Jones.
The lawyer said he had described how he had been going down the wrong path in life but had changed his ways.
Ms Jaquiss told jurors at the inquests that she had invited Khan to come and sit at a table to take part in a group discussion during a workshop.
Asked how he seemed, she said: “Perhaps a little shy. I didn’t notice anything out of the ordinary at all at the time.
“I remember him saying something to the effect of he had been involved with a group of people who had been leading him down the wrong path.
“He had now seen that way was wrong and he was now essentially turning the other way or going a different way.”
A statement from Millicent Grant, a legal executive who sat at a nearby table, said: “He wasn’t animated, he was sat back in his chair, straight faced and with a clear, steady voice.”
Khan was wearing a padded jacket at the conference, and jurors heard a statement from Cambridge PhD student Benjamin Jarman, who had planned to ask him if he was warm.
In his evidence, read by counsel to the inquest Aaron Moss, Mr Jarman said: “He was looking anxious… I was going to ask him where he was from and mention he must have been warm in his coat.”
It was later discovered that Khan was wearing a fake suicide vest.
Ms Jaquiss said that after a refreshment break at the end of the workshop, she heard screaming and grunting coming from downstairs in the building.
The barrister, who knew Mr Merritt from her previous involvement with Learning Together, told the jury a man came into the room “who said there is a man downstairs with knives and a bomb strapped to him”.
“I was certainly very scared and I suppose frozen to the spot a little bit, not knowing what to do.”
Jury inquests into the deaths of Mr Merritt and Ms Jones are taking place before coroner Mark Lucraft QC.