Sen.-elect Cory Booker is set to become the most junior senator on Halloween.

The office of Vice President Joseph R. Biden Jr. confirmed that the New Jersey Democrat will be sworn in at noon on Oct. 31. The mayor of Newark easily prevailed in the Oct. 16 special election to fill out the unexpired term of the late Frank R. Lautenberg, a fellow New Jersey Democrat.

The incoming senator’s chief of staff should be a familiar face to Biden. Booker announced that Louisa Terrell of Facebook would lead his Senate operation. Terrell was a senior aide to the vice president during his days as a senator from Delaware.

Booker will take over from Sen. Jeff Chiesa, R-N.J., the interim senator appointed by GOP Gov. Chris Christie.

The swearing-in will bring to 55 the number of senators caucusing with the Democrats, giving one more vote to Majority Leader Harry Reid as the Nevada Democrat looks to push forward with a fall agenda truncated somewhat by the government shutdown.

No word if anyone will appear in costume, though it wouldn’t even be the first time someone dressed as Biden during official Senate business. Current Defense Secretary Chuck Hagel did just that back in 2007, when both were members of the Foreign Relations Committee.