A 17-year-old boy was "ambushed" by a group before being stabbed and left to die in a shipping container yard, a court has heard.
Newport Crown Court heard Harry Baker was subject to a "swift, bloody and merciless attack" in Barry Docks, Vale of Glamorgan, in August 2019.
Jurors were shown footage of an ambush the defendants were said to have carried out on Mr Baker and his friend.
Six men and a boy, who cannot be named for legal reasons, deny murder.
The prosecution has suggested the motive for the killing was drugs.
Leon Clifford, 23, Raymond Thompson, 48, Lewis Evans, 62, Ryan Palmer, 34, Peter McCarthy, 37, all from Barry, Leon Symons, 22 from Ely in Cardiff and a 17-year-old boy who cannot be identified, all deny murder.
Mr Clifford has pleaded guilty to manslaughter.
Mr Lewis said two of the defendants had been "lying in ambush" and appeared from a grassy area while on the phone to another defendant.
"A shiny implement can be seen in the hands of one," Mr Lewis told the court.
CCTV footage from across the town then showed Mr Baker and his friend being chased for about a mile. The court was told the 17-year-old defendant had been "leading the chase".
Jurors were shown the moment some of the defendants reached the locked Intermodal yard in Barry Docks.
Mr Lewis QC said: "Ryan Palmer is armed with a piece of wood, McCarthy has got a piece of wood and a knife."
Footage showed some of the defendants climbing the fence, which left "three of the five, all armed" in the compound, according to Mr Lewis.
Jurors were then shown footage of four of the defendants leaving the yard on 28 August, while Mr Baker was "lying dying" inside.
'Sharp, forced injuries'
Mr Baker was found with nine "sharp, forced injuries", stabs and slashes, to his head, face, neck, and body, the court heard.
Mr Lewis QC said Mr Baker was "lying face down and was dressed only in his boxer shorts and socks" when found by an employee at the docks at around 05:45 GMT in the morning.
The court heard a wound in the teenager's stomach caused "profuse bleeding" in his body, which led to his death.
He said it was thought the boy had survived for up to three hours after the attack.
'Laughing on the phone'
The prosecution said the victim's phone was taken by the defendants after the stabbing, and defendant Mr Symons answered that phone after the attack.
Mr Lewis QC said Mr Symons "showed not one jot of remorse or regret" on the phone, and was "laughing on the phone" to the person who had called Mr Baker.
Jurors were told Mr Symons had said: "Your boy is dead now, you ain't finding him".
The court heard another call was made after the stabbing, this time from Mr Bakers's phone to a woman he was staying with at the time.
Mr Lewis QC told jurors the caller, who had tried to disguise his voice, said: "Ha guess whose phone I'm ringing you off? We've got your boy's phone, you won't be hearing from him again".
There was a real likelihood the teenager was still alive when that call was made, but the defendants "did nothing to help him", the prosecution said.
The court heard five of the defendants "make their escape" in a Nissan Juke driven by "getaway driver" Lewis Evans, 62, who dropped two of the defendants in Barry and three in Cardiff.
The trial continues.