Investors in Europe are calling today “Super Thursday”: the day when the head of the European Central Bank Mario Draghi rides to the rescue and saves the euro. This afternoon Draghi unveils his much-heralded plan to end the eurozone debt crisis.

Draghi has promised to do whatever it takes to stop the debt crisis. Today he’s expected to spell out the details: a plan to print money and buy vast quantities of government bonds, especially those of weaker economies like Spain and Italy. That should drive down their borrowing costs, stave off the danger of default and take pressure off the euro.

“Oh Mr Draghi, please deliver!” said Louise Cooper of the BCG financial group. She said investors are pinning all their hopes on the man they’re now calling “Super Mario.” “If I were religious, that would be my prayer. Mr. Draghi, don’t disappoint.”

There is much scope for disappointment. Germany’s top two economic officials have deep misgivings about the Draghi plan. It may be watered down as a result.