Armed police swooped on a sword-wielding knight - on his daily exercise in his medieval fancy dress.
Three officers from the firearms unit were called after families spotted the mystery knight at a lake beauty spot.
The 999 callers feared the mystery swordsman would launch an attack with the three-foot weapon.
The "knight" was confronted at gunpoint - and was shocked to be ordered to put down the blade.
Police saw the funny side when they discovered it was fake - and that Sir Laughalot was out for a walk in his fancy dress at Hendre Lake, in St Mellons, Cardiff.
Medical technician Mike James, 31, was walking around the beauty spot with his wife Heather, 32, and son Theo, three, when he saw the knight drama.
The whole thing was really surreal - he looked like something out of Assassin's Creed.
Mike had his camera with him to take pictures of his son riding his bike and the ducks in the lake when he captured the drama.
He said: "The police ordered him to put the sword down and then they confronted him.
"They had a chat with him for a couple of minutes and apparently the guy told them he was trying out a new outfit and he was walking around the lake to get used to the weight.
"The armed police were good as gold and even had a picture with him afterwards before letting him go on his way.
"I don't know what the sword was made from but it looked real enough!
"The outfit did look heavy - I'm not sure it was proper chainmail but it made a real tinny noise as he was walking past."
At 3.10pm on Wednesday 13th May, South Wales Police received a report from a member of the public that a man was seen at Hendre Lakes in Cardiff with a sword. Officers were deployed to the scene where they located a young man who was in fancy dress carrying a toy sword. No criminal offences were committed and the man was given suitable advice.