Two men hatched a plot to rob and kill international pop star Joss Stone before dumping her body in a river, a court has heard.
Junior Bradshaw and Kevin Liverpool harboured deep hatred for the soul singer, who they referred to as a "she-devil", it is claimed.
The pair set off from their home in Manchester with a samurai sword, knives, bags and gloves crammed in their Fiat Punto, bound for Miss Stone's address in mid-Devon, Exeter Crown Court was told.
It is claimed the alleged murder plot was fraught with problems.
The pair were spoken to by police having been involved in a crash on the journey south. They also asked a postman for directions to Miss Stone's home using a picture of the pop star in an attempt to track her down, the court heard.
The duo had previously gained evidence about one of Miss Stone's former homes, near Cullompton off the M5, after studying a video documentary she made for MTV's Cribs series and printed Google street maps to find her new address a short distance away, the prosecution allege.
It is claimed that notes found in the defendants' possession showed they intended to decapitate the pop star before planning to dump her body in a river.
The pair were arrested a few miles from Miss Stone's home, the jury heard.
Bradshaw, 32, and Liverpool, 35, deny charges of conspiracy to murder, conspiracy to cause grievous bodily harm and conspiracy to rob, in 2011.
Opening the case, prosecutor Simon Morgan QC told the jury of 10 men and two women: "This case is about a decision by a group of individuals, of which these defendants are two, to rob and kill Joss Stone.
"That is not a phrase I have plucked from the air. It is used in documents written by Mr Liverpool during the planning stages of this plot. We don't know who the others are but that does not matter.
"Your job will be to determine whether you think these two are part of a plot."
The court heard the duo went on at least one fact-finding visit to the area in the weeks leading up to 13 June 2011, when they were arrested a few miles from Stone's home.
They aroused suspicion, the court heard, because their vehicle was not known in the area by neighbours in the "eagle-eyed community".
Both men told police they were lost and were trying to get to Bristol. Bradshaw also told police they had been stopped a few miles away and the vehicle had been checked before being given the all-clear to carry on their journey.
But it turned out the pair were stopped at the Michaelwood service station on the M5 just north of Bristol shortly after 5am. They had been involved in a collision with metal railings and a digger, leaving the Punto badly damaged.
Mr Morgan said: "Normally vehicles would be seized if the driver did not have insurance but, because the vehicle was badly damaged, the decision was made that it would not be seized: the damage was such that a sale of the vehicle by the authorities would not cover the costs.
"Furthermore the officers took the view that it appeared to be immovable without significant assistance. The police therefore left."
It allowed Bradshaw and Liverpool to continue their trip south, in the accident-damaged Punto.
But they became lost around seven miles from Miss Stone's home, the court heard. They showed local postman Alex Greening a map with handwritten notes on it, as well as a picture of the 25-year-old soul singer.
When asked, Mr Greening said he did not know where Miss Stone lived, the prosecutor said.
Suspicious neighbours called the police and when their vehicle was eventually searched, officers found a stash of weapons. These included a sword, a section of hosepipe, a £1 hammer, and a further holdall containing a spike, black bags and tape.
A search of the pair's home in St Stephen's Close, Longsight, Manchester, also recovered a self-cocking crossbow and a BB gun.
Mr Morgan said: "In interview, the defendants, in essence, declined to comment. The items in their possession, the trips to the area, the fact that the intended victim was at home, the notes and maps all point to a determined effort on the part of the defendants to carry out the plan they had hatched some time before.
"The evidence established that they intended to rob and kill their target using the equipment they had with them."
He said handwritten notes found after their arrest mentioned murder. One made reference to "kills" and "decapitate", another read "Jocelyn RIP", while another said: "Once Jocelyn's dead... find a river to dump her."
Jury members were told a motive was "irrelevant", but said the notes offered some clues about why they are alleged to have targeted Miss Stone.
Mr Morgan said the documents also "appear to express disapproval of the Royal family".
He said: "Joss Stone associates with members of the Royal family; her concerts have been attended by members of that family and she was invited to the Royal Wedding (Prince William and the then-Kate Middleton) at the very end of April that year. Hence, the Crown say, she was a target."
He said one note added: "The Queen - she-devil. But she likes Joss Stone. Invited to Will's (Prince William) wedding by Queen. Where's the sense in that?"
Bradshaw, 32, and Liverpool, 35, deny all charges.
The trial is expected to last for up to three weeks.