Alan Hocking bundled Michael Roberts, 18, into the back of his car and drove around the coast near Seaham, Co Durham, for half an hour, looking for a quiet spot to throw his captive into the water, a jury at Teesside Crown Court heard.
When his plan failed, he allegedly dragged Roberts from the car, then kicked him and beat him senseless with a lump of wood studded with nails.
The court heard how Hocking, 27, an unemployed butcher, of Murton, Co Durham, snapped when he discovered his friend's 14-year-old son was buying drugs. The boy admitted buying two tablets of LSD, worth pounds 3 each, from a school friend at Easington Comprehensive.
Hocking confronted Roberts, whom he had been told had supplied the drugs, at his home in Seaham, then dragged him by the throat into his Ford Fiesta.
Peter Johnson, for the prosecution, said: 'What followed was an extremely frightening and threatening experience, which lasted 30 minutes, for young Michael Roberts . . . The defendant told Mr Roberts: 'This is for giving drugs to a 14- year-old kid.'
'Roberts was extremely frightened and they drove towards the sea, but a gate was locked and they couldn't get through.
'It was then the defendant said: 'That's a pity, I was going to throw you off a cliff.' '
The court heard that Hocking drove north up the A19 with his prisoner trapped in the back of the car. His plans were again thwarted as they drove down to the sea because another car was parked near by. Eventually he parked beside a railway bridge and attacked Mr Roberts. Mr Johnson said: 'He punched Mr Roberts in the jaw and he fell down. He then subjected him to kicking about the body and legs. He was also hit several times across the hands with a stick which had nails in it.
'The stick broke and left bruises and puncture holes in Roberts's hands. It was a wholly unjustified, unlawful and unprovoked assault . . . He had no right to take the law into his own hands the way he did.'
Hocking denies kidnapping, false imprisonment and assault causing actual bodily harm, following the incident last March.
The trial continues today.Reuse content