Elaine O'Hara received a text message from a man alleged to be Graham Dwyer stating that he planned to kill an auctioneer, the Central Criminal Court has heard.
The trial of the Cork-born architect, who denies murdering the 36-year-old childcare at Kilakee forest in the Dublin Mountains on August 22, 2012, has heard that Mr Dwyer told Ms O'Hara he found an empty house in Cabinteely.
The man alleged to be Mr Dwyer, with an address at Kerrymount Close, Foxrock, named the "young pretty auctioneer" as Rowena Quinn, an auctioneer who has given evidence in the trial.
In the text message exchange on August 3, 2011, the man whom Ms O'Hara addresses continually as "Sir" outlines how he will rape and stab Ms Quinn to death in Willow Park, Druids valley, Cabinteely.
Ms Quinn earlier told the trial she was selling a house there.
Ms O'Hara texted later that she thought it was "too close" to home and to her work.
The trial of seven men and five women has heard details of some 2,600 messages alleged to have taken place between Ms O'Hara and Mr Dwyer.
The phones include messages sourced from Ms O'Hara's iPhone and an 083 number allegedly used by Mr Dwyer as well as two pre-paid mobile phones in August 2012 that were recovered from the Vartry reservoir in September 2013.
Ms O'Hara went missing on August 22, 2012. The trial has heard that she was last seen by a jogger in Shanganagh Park on the evening of August 22, 2012, hours after being discharged from St Edmundsbury Hospital in Lucan. Her skeletal remains were found in a forest at Kilakee on September 10, 2013 after being found by a dog walker.
Crime and policing analyst Sarah Skedd gave evidence yesterday of text messages sent between two phones in the week before Mr Dwyer is alleged to have murdered Ms O'Hara.
The trial has already heard that the Nokia phones had been purchased together and used only to contact each other. They were found in Vartry Reservoir in late 2013, along with keys to Ms O'Hara's car. Each had only the phone number of the other phone saved in its contacts: SLV and MSTR. The prosecution has referred to them as the 'Master' phone and 'Slave' phone and alleges that they were being used by the accused and the deceased.
Ms Skedd said text messages from August 14 to August 22 were recovered from the phones, a period when Ms O'Hara was a patient at St Edmundsbury Hospital.
The court heard that Ms O'Hara, who was desperate to have a baby, received a text from the Master phone on August 21, 2012 - the day before she was discharged and went missing - that she had to be punished for trying to kill herself without him and for being unavailable to him.
In one exchange, Ms O'Hara said she supposed she had a punishment coming up and suggests "bread and water for a week".
However, Master says: "Its up to me and you have a big punishment coming up, knife in the guts," adding that she will be bound, gagged and tied to a tree deep in the forest. "I found a really, really remote place no one will find us," said the Master.
Ms O'Hara, using the Slave phone, texts that she is frightened and says that he will have to drag her out of her apartment. Later that day, after the Master confirms she will have to drive part of the way to "the spot" he picked, Ms O'Hara - who is due to see her counsellor - texts that she is "really scared".
The Master tells Ms O'Hara that no one, including Ms O'Hara's counsellor, should know about him. On the day she left St Edmundsbury, Ms O'Hara again told the Master that she is "terrified".
The court also heard a series of text exchanges about Ms O'Hara's desires to have a baby with the man alleged to be Mr Dwyer.
In one exchange, Ms O'Hara is angry at "Sir" because she can not afford to have a baby. The man offers to pay her in exchange for "play". But Ms O'Hara replied: "I'm not a prostitute. I'm a person. I have dignity."
Trial Judge Mr Justice Tony Hunt told the jury that closing speeches are set to commence next Thursday and Friday after Mr Dwyer's defence leads evidence in the trial.