By Ross Hawkins
BBC political correspondent
British voters are used to seeing triumphant prime ministers on the steps of Downing Street after election day.
This year things may be very different.
Who will move into this famous address may not be obvious
The Conservatives are set to make big gains, but the exit poll suggests they may not be sufficiently large to give David Cameron an overall majority.
Labour has lost many seats, but not yet its prime minister.
As the incumbent at Number 10, it is down to Gordon Brown to decide whether he can do a deal to stay in power, or whether he should resign.
The Liberal Democrats seem set for disappointment.
A party that had the highest hopes after the TV debates may have to make do with a middling performance.
The party leaders' statements at their counts were inconclusive.
David Cameron said Labour had lost its mandate to govern.
Gordon Brown said it was his duty to play a part in Britain having a strong, stable government.
They - like the rest of us - do not know what will happen next.
Each party has had its triumphs and disappointments.
The Liberal Democrats lost
and one of their most colourful figures, Lembit Opik, with a 13% swing to the Tories, and Evan Harris in Oxford West. But the party gained Eastbourne from the Tories.
The Conservatives won many seats, but failed to eject Labour candidates they had hoped to defeat like Sadiq Khan in
and Gisela Stuart in
Labour saw two former home secretaries defeated in Jacqui Smith and Charles Clarke, but the schools secretary Ed Balls and former communities secretary Hazel Blears escaped with their seats.
In some cases, voters appeared to be making decisions on local rather than national issues.
where the steelworks have been mothballed, the Labour MP Vera Baird was ejected with a huge swing to the Liberal Democrats.
Others missed out on their chance to have a say.
At polling stations across the country, queues of people were still standing outside when the doors closed.
It led to some angry scenes, and may yet result in legal challenges from disappointed candidates.
The party leaders now have to make sense of a confusing situation.
If it results in a Conservative overall majority, things will be simple.
If it does not, Gordon Brown may try to do a deal with the Lib Dems.
If he fails or does not attempt that, David Cameron will have to decide whether to rely on a loose agreement with minor parties, to encourage the Liberal Democrats to support a Tory Queens Speech and Budget, or try to entice Nick Clegg with a place in a formal coalition.
Should the general election of 2010 end in that sort of deal making, the true outcome could be some time coming.