It's transfer deadline day, and as it does twice a year, the world of football goes into meltdown.
With over half of all deals in the January transfer window taking place on deadline day, most Premier League clubs, agents, officials and players are frantically calling, texting and for some reason still faxing like crazy in the hope of making that dramatic last-gasp move happen.
But what happens once a fee has been agreed between two clubs and a contract has been signed? Many a deal has been scuppered at the last minute because of complications.
Joao Moutinho seemed destined to complete his move to Tottenham in the summer only for the north London club to run out of time. Conversely, Spurs managed to get Clint Dempsey's move over the line after the window had firmly snapped shut.
Well it turns out that not only have clubs got to deal with slippery agents and demanding players, they've also got to get clearance from the Premier League and get all their paper work in order before they can make their new signing official.
The first hurdle that must be cleared is making sure the Premier League have all the correct documents - that includes the notoriously tricky work permit.
Most Football Manager regulars will be familiar with the frustrations of rooting out a Brazilian starlet only to see the move falter over work permit issues, and the same thing happens in real life.
Players from non-EU territories have to fulfill certain criteria - for example they have to have played 75% of their countries international fixtures. Frustratingly for Premier League, other countries like Italy, Spain, France and Germany don't have to jump through such awkward hoops.
For example, pretty much all of the great South American players like Ronaldo, Ronaldinho and Lionel Messi go to other European leagues upon arriving on the continent. In fact, Chelsea's Oscar aside, it is hard to think of a mercurial youngster from outside Europe that has gone straight to England.
Of course with lots of deals taking place on the final day of the window, the Premier League brace themselves for the impending storm. They ask all 20 clubs if they intend on signing anyone so they can ready themselves to get the paperwork through in time. They also deploy extra staff to deal with queries late into the night to help push deals through, and won't go home till the last one is signed off.
Once a deal is agreed between the two clubs and the player, all the documentation, including contract, transfer fee agreements and international clearance, are checked to see if they comply with FA and in some cases FIFA rules.
The Premier League say they process the information immediately in order to let clubs know if they can complete the transfer. To give you an indication of how busy it can get on deadline day, they say that in the space of one hour last year, details of 30 transfers were sent through for processing.
But clubs don't just leave signing players to deadline day; sometimes they leave it quite literally to the last minute.
That means there isn't time to get all the documentation to the Premier League before the window slams shut at 11pm. That's where the mythical 'deal sheet' comes in.
Introduced two years ago, the deal sheet allows a club to confirm a deal before the window closes and then sort the documentation, which then has to be with the Premier League before 1am, or 12am if the player is being signed from a foreign club. The sheet cannot be used prior to 9pm.
That's not the end of the story however, not by a long way. When the deal involves transferring a player from an international club, it must be registered on FIFA's Transfer Matching System.
The buying club has to upload the details to the system, then the foreign club have to match those details; otherwise a deal won't be given the green light.
"Our FA will request clearance and as long everything matches; the foreign association will issue clearance to the FA, who then informs the club and League," as the Premier League puts it.
It's no wonder it is so difficult to get a deal through in time, Tottenham must be kicking themselves for leaving it so late to try and get Leandro Damiao on board.
Spurs have also felt the effects of the next stage of completing a transfer. the Premier League forbids third-party ownership - said to be the snag which crucially held up the deal for Moutinho.
Then comes the infamous work permit, although the Premier League allow clubs to put an appeal to a panel if they don't fulfil the initial criteria . A transfer can then be cleared if they believe the player is of the highest quality and can 'contribute significantly to the development of the game at the top level in England'.
So after all the hard work, millions of pounds and blood sweat and tears it takes to get a deal through in time and complying with all the rules, it all comes down to one thing. The legendary last-minute fax.
Unfortunately, the Premier League dispel the notion that multimillion pound international deals hinge on a technology last used in 1986. They say clubs can just email them the scanned documents instead. They do still use the fax, and allow for exceptions, presumably for things like paper jams.
So there you have it. Once all the criteria is met, paper work is signed off and details logged, a player is free to sign for whichever Premier League club he chooses. So fans can sit back and enjoy the action unfold as the minutes tick down, while Premier League officials and clubs scramble round, trying to figure out how to send a fax at 10.59pm with a £100 million deal for Cristiano Ronaldo in the balance. It should be fun.