Grate the lemon rind being careful not to grate any part of the white peel
In large skillet over low heat steep cream and lemon zest for 5 minutes. Add vodka and stir in juice of half of the lemon and nutmeg.
Drain the pasta when it is barely al dente and add to the sauce in the skillet. Raise the heat to medium and stir and toss the spaghetti until they have absorbed most of the liquid and sauce is creamy and thick.