We've been running parties on the London Underground for years. In our minds it's a public space, a space in our city London where people often get cramped in so tight you spend entire journeys with your face squashed up against some sweaty city boy's armpit. Yet a space where people don't talk to each other. Tube journeys are spend looking but not interacting, peeking over people's shoulders to read the paper, but not making small talk. Getting intimate with squished up close body parts, but not knowing each others names.

So we thought why not hold a social, hold an event on our tube where people feel encouraged to chat, encouraged to share drinks and encouraged to have a little dance. It's a public space in our city, a city where the decisions and control have been taken out of the hands of the users of that city, so why not have a little experiment to live by a different set of rules.

Our first party in 1999 had about 150 guests, the second around 600, the third around 2000, after that we went underground, with just one more secret one for our friend. As we'd hoped the idea would catch, alas they didn't all read the rules.

After the mayhem of protest against Mayor Boris' decision to ban drinking on public transport, and then the silly decision to turn the "Circle Line" into a spiral, we thought the Circle Line Parties were dead and buried. Then Agent Hardcastle told us the news one meeting.

"TFL are doing engineering work on the circle line, for two weeks they are going to turn it back into a circle, we've got a small window of opportunity for a final bash"
Game on we thought.

So..how to stop it turning into a social networking, unsociable disaster? We came up with the 'whites of their eyes' plan. You can't tell anyone about You Know What unless you can see the whites of their eyes. This, combined with a very very last minute non-whites of eyes mail-out meant we had a very respectable number of revellers. Enough to make a party, but not so many that it becomes mayhem.

With the ban on booze on the tubes, we decided to theme the CLP a Prohibition-style event. Armed with natty costumes, gin in teapots, appropriate tunes and a tube-themed pole for dancing (ahem) we were ready!

The evening arrived and we rolled up at Liverpool St Station. Amongst the commuters an ever growing number of people with 20's style head dresses, slick pinstripe suits and a number of large cases began to mingle. Furtive glances were dashed across the station platform as guests tried to guess who else was here for the party and who just happened to be on their way home. The pre-chosen train finally pulled into the station as the buzz was getting to fever pitch and we were about to give the game away.

Within seconds of the doors closing and the train pulling into the tunnel, the hijacker crew had leapt into action. Coloured gels were being taped over the horrible strip lights, cables for our sound system were being strapped around the train, our pole dancing podium was slotted together and teapots full of liquor were being pulled from handbags as hip flasks were slipped out of jacked pockets.

The rules of Circle Line Parties are quite simple
1 - the party only happens in the tunnel, when we're in a station shut down the sound system and everyone act normal
2 - if someone looks like they got on the train by accident, offer them a drink and make friends
3 - no-one organised this, we're all here by chance
4 - clean up and leave the train tidier than when we got here
5 - fill up the train from the back carriage so that the driver can't here you

As our speakeasy rolled it's way clockwise around the metropolis the party got into full swing. Litereally, with agent Invisible Parsnip boarding the train and attaching her tube train swing to the handrails of our carriage.

Random commuters were staying on for extra stops, changing their journeys to accommodate more party time and sipping from china cups full of moonshine!
Alas as the train pulled into Kings Cross tragedy struck. The train came to a halt, the doors slid open and we sat there, and sat there, and sat there. Our quiet, well behaved group (see rule 1 above) began to smell a rat. Then the carriage speakers crackled into life:

"Ladies and Gentlemen, we're sorry for the delay, we're being held at this station whilst British Transport Police investigate a party being held in the back carriages"
ABORT, ABORT, ABORT!!!!!

Quicker than rats leaving a sinking ship, the gels were packed away, the stereo stuffed into cases and the rubbish grabbed and dumped into bin bags. We rushed out of the platform and began to make our way up the stairs as the Police came charging down them. EEEK!

As the two groups met each other, we braced for the inevitable long hand of the law to grab us, before they suddenly shoved past us grumbling as they attempted to get to the offending (now empty carriage). With a hop, skip and a jump the vast majority of us had flowed out of the barriers before the police had realised their mistake. The sound system, podium, and all of the other kit was safe, all that was left for them to do was coral some sequin clad ladies and ask about their empty teapots.

We reconvened outside and decided that this could not be the end of the night. We were determined to make a full lap of the circle on this final hurrah. Jumping on a bus to Farringdon, we resisted the temptation to inaugurate a routemaster party, after a quick toilet break in some ghastly weatherspoons pub (they are good for something) we were back on the platform and awaiting our next chariot.

We were joined by more agents and the game was back on. Dancing as we trundled through the belly of London the ridiculous alcohol laws were ignored by our dapper flappers and our fellow commuters threw themselves into the party. The timing of CLP's is very important, if you have them too early, people are still trying to get home, too late and everyone is already trashed. We were careering around in that perfect moment, where the trains are full of people who've either stayed out for a drink after work, or are on their way out for the night.

As usual by the time of our second lap the switching off of the stereo was getting a little slacker, and "acting normal" in the stations was getting a little less well acted. However it seems the god of illegal raves was shining on us as we pulled into Kings Cross for our second time that evening. We took a deep breath and fingers and toes were crossed. Beep, beep, beep, the doors closed, the train pulled out of the platform and a cheer went up from Hijackers and commuters alike.

A few more stops and Liverpool street was back on our horizon, our dancing mob was getting out of control and the call for a urinal was getting deafening, so we decided to call the evening to a close before the police tried again. Falling out of the station and heading back into the East End we waved goodbye to the circle line, a piece of public transport that has given us so much fun over the years, and looked forward to our next underground adventure (details of which are still top secret at the time of writing...)