Fill the second cup of wine. Tell the story. When you get to the description of the plagues, remove a little bit of wine from the cup at the mention of each plague. When you get to the happy ending, pick up the wine cup and recite:

Baruch ata Adonai Eloheinu melech ha'olam asher g'alanu v'ga'al et avoteinu mimitzrayim, v'higiyanu halailah hazeh le'echol bo matzah umaror. Ken Adonai eloheinu velohei avoteinu, yagi'einu l'mo'adeinu v'lir'galim acherim haba'im likrateinu l'shalom, s'meichim b'vinyan irecha v'sasim bavodatecha, v'nochal sham min haz'vachim umin hap'sachim asher yagia damam al kir mzbachacha l'ratzon. V'nodeh l'cha shir chadash al g'ulateinu v'al p'dut nafsheinu. Baruch ata Adonai, ga'al Yisrael.

Baruch ata Adonai Eloheinu melech ha'olam borei p'ri hagafen.

Which means approximately:

We bless you, Lord our God, ruler of the world, who saved us and our anscestors from Egypt and brought us to this night to eat matzah and maror. In the same way, may the Lord our God and God of our ancestors bring us in peace to future holidays, and may we be gladdened by the rebuilding of Jerusalem and happy in serving you, and may we be able to eat the Passover offering there, according to your will. And may we have the chance to praise you with a new song for saving us and making us free. We bless you, Lord, who has saved Israel.

We bless you, Lord our God, ruler of the world, who creates the fruit of the vine. 

And then you drink.

haggadah Section: Maggid - Beginning
Source: Unknown