By Dickon Hooper and Liz Lewis
BBC News Online, Bristol
It is 1800 BST on Wednesday and the latest flash mobbing hit is about to take place.
BBC Radio 5's Phil Mackie [fifth from right] joins the fray
The instructions are very clear and are not to be strayed from under any conditions.
The star sign of every participant determines a meet up in one of two pubs. Once in, we are to make contact.
Flash mobbing: a technology-inspired craze of random acts committed by spontaneous crowds - and it has reached Bristol.
Between 1800 and 1815 BST, contact is made with a shaven-headed man wearing a black T-shirt with a skull logo, near the fruit machine of a Bristol pub.
If we were early, we were told, blend in and buy a drink: do not act suspiciously.
On our second approach to the man in black, after a swift half, we are handed a piece of paper on which is written a series of instructions.
It is the first time we have been told what we will be doing: the silent conga.
Firstly, we swap mobile numbers with someone else in the know in the pub - but discreetly: although the bar man has already clocked that his shift is busier than normal.
And at precisely 1830 BST, we walk out in front of the Bristol Hippodrome in the centre of Broad Quay, nervous, wondering how people will react.
The man in black turns to the group and says: "I think I hear conga music".
This is our cue.
More than 60 people form up, mouthing "Ooh, ooh, ooh, come on and do the conga": and we dance, for exactly three minutes.
The conga lasted three minutes exactly
Maybe not as grand as the first New York hit - but it goes down well with the assembled crowd.
At 1833 BST, amidst a chorus of mobile calls to each other, the crowd stops, grins and disperses - as if nothing had ever happened.
One of the organisers, who prefers to remain anonymous, told BBC News Online: "You must understand what this is all about, but especially what it's not about. The main element is fun.
"Nothing else must interfere - political messages, rights of groups or individuals, religion and products for example - there are plenty of platforms and outlets for these issues already. Flash mobs are not one of them."
The first reported flash mobbing hit was at a department store in New York in June, where mobbers broke into spontaneous applause.
In London on 7 August, a gang of people stared at a sofa and in Boston, crowds swamped a card shop.
This was Bristol's first taste - and revellers had a mixed reaction.
Robin Davey said: "I am tired and out of breath: I think we needed to limber up beforehand."
While 'Barry' added "It was a bit disappointing - not up to New York standard.
"I didn't know anything about this before I came: I heard through friends."