In 1864, the body of a wealthy banker was discovered on the tracks between Bow and Hackney Wick stations in London. But the death of Thomas Briggs was no accident - it was the first murder on a British railway. The pressure was on for police to solve the crime, but nobody could have predicted the drama that was to come - the desperate flight of the killer and the cross-Atlantic race to bring him to justice.

Percy Lefroy Mapleton was a talented young writer. But he was also a liar, a thief and a fantasist. By 1881, he had become fixated on a beautiful stage actress. Convinced the two of them belonged together, he concocted an elaborate fraud to win her heart. But Lefroy could not outrun his lies forever and, when exposure seemed certain, he was driven to a darker and more violent crime.

On a September night in 1895, two railway policemen surprised a gang of thieves at work in a Wigan goods yard. A vicious fight broke out and Detective Sergeant Robert Kidd was stabbed to death. It was the first time a railway police officer had been murdered in the line of duty. But bringing the killers to justice would not be easy. The gang was fiercely loyal and there were no other witnesses to the crime. If there was to be a conviction, one of them would have to talk.

In 1910, the city of Newcastle was transfixed by a murder trial. A clerk had been killed on a train and his wages bag stolen with hundreds of pounds inside. Accused of the murder was a local man named John Alexander Dickman. But the evidence against him was all circumstantial and, thanks to a recent change in the law, Dickman himself would have the chance to go into the witness box. Dickman was a professional gambler, but he had never faced stakes like this. If the jury believed him, he would walk free. If they didn’t, he would hang.

Jimmy Alcott was a troubled young man. He had joined the army after leaving school, but his time in Germany ended in disgrace when he was court-martialled for the violent murder of a civilian. Spared execution by the mercy of the King, he returned to England and built a new life for himself. He had not left his violent ways behind however. In 1952, he travelled from his home in London to the village of Ash Vale in Surrey. There he staked out the railway station and plotted a theft that would end in murder. But would Alcott escape the noose a second time?

It is one of London's great unsolved mysteries. Late one evening in May 1957, an elderly Polish Countess was travelling home from a party when she was attacked at Gloucester Road Tube station. Stabbed repeatedly on the platform, she died in hospital later that night. Her killer was never identified and, to this day, there are only theories about why Countess Teresa Łubieńska was targeted. But could there be a clue in her past? The Countess had a remarkable life. She was a film-maker, an activist, a poet, a resistance fighter and a concentration camp survivor. She was an extraordinary woman. And somebody wanted her dead.