A graphic designer attempted to poison her magistrate mother in a plot inspired by TV series Breaking Bad, a court has heard.
Kuntal Patel allegedly laced her mother Meena's drink with Abrin at her home in Stratford, East London, after the 60-year-old forbade her from marrying her boyfriend.
An FBI investigation found Patel had bought the poison, described as "much more poisonous" than Ricin, online, Southwark Crown Court in London was told.
But Meena survived as the poison, which was delivered in a candle from the US, is 1,000 times less deadly if swallowed rather than inhaled or injected.
Prosecutor Jonathan Polnay told the jury: "Inspired, in part, by the US television series Breaking Bad, she acquired a deadly toxin called Abrin, a close relation to Ricin, which you may have heard of. She acquired it over the 'dark web' from a vendor in the USA.
He added: "The deadly toxin arrived from the United States concealed in a wax candle. Kuntal secretly poured the Abrin into her mother's Diet Coke and watched her drink it - expecting her to die. But nothing happened."
Patel denies trying to murder her mother and acquiring a biological agent or toxin. She has admitted two counts of attempting to acquire a biological agent or toxin last December.
Breaking Bad followed the tale of Walter White, a chemistry teacher who becomes a crystal meth manufacturer to provide for his family when he is diagnosed with terminal cancer.