Mr Margolis, 29, a project manager at Digiterre software company in Hammersmith, had been in the first carriage, close to where the bomb detonated and was among the first survivors to walk the track and emerge at King's Cross station.
But he was determined not to let the attack destroy his life. "My first reaction was, 'I'm never getting on the Tube again' and I was petrified," he said. "But then I wanted to make sure this thing did not get the better of me or disrupt my life. I took the day off and my wife and I got a taxi to central London but decided we would get the Tube home on the Victoria line from Euston.
"I went quiet as I went down the escalator. I thought I'd be very afraid but it felt normal. I talked to my wife through the journey and felt fine but I don't know how I will be by myself. The next milestone is to get the Tube on my own on Monday and not getting scared when it jolts."
After the blast, Mr Margolis had head injuries. He was given water and called to his wife, Sarah, and relatives.
Mrs Margolis, 28, a producer in an interactive agency in central London, said she barely recognised her husband.
"His face was black from soot, he had blood running down his face, neck, chest," she said. "His white shirt was covered in blood. I ran up to him and gave him a big hug."
The couple walked to the Royal Free Hospital and Mr Margolis had glass removed from his head.