General Election 2015: Greens want Labour to help achieve their goals
The Green party want to tax more and spend more, and persuade Labour to do the same thing.
Some senior Greens are explicit: their target is the shadow chancellor Ed Balls; his plans are the ones they seek to change.
Their dream: joining forces with the SNP and Plaid Cymru in a hung parliament, and dictating terms to a minority Labour administration.
Their method: policies that Labour voters, and Labour MPs, might be persuaded to support.
At their conference in Liverpool they demanded free care for over-65s and a bill to strip any market mechanism from the NHS. Their demands, some calculate, might find favour with many in Ed Miliband's party.
For the Greens to play a central role at Westminster, though, the Conservatives must lose, Labour flounder, and a loose alliance of the SNP, Plaid Cymru and the Greens must flourish. It is heady stuff, but the realities are tough.
Above all, the Greens have to keep hold of their single MP Caroline Lucas in Brighton and Hove. The Green council there is embattled; the election contest will be difficult.
If Lucas wins in May, the Greens will be set to enjoy a decade in the House of Commons. If she loses, her foray to Westminster could be seen as a blip.
The party has enjoyed unprecedented levels of attention, and by its own standards heady heights in the polls.
To realise its dream of a "progressive alliance" in the House of Commons, though, it needs a lot of hard work in the constituencies where it matters most, and a great deal of luck.