Will is Castle gonna call for a major guest-starring spot this Halloween? Dan Akroyd, says executive producer Laurie Zaks.

"We're planning a Ghostbusters-themed episode to air on Halloween night," the executive tells TV Guide Magazine, adding that other holiday-themed installments are also on tap. Most notable?

A Christmas episode that will likely introduce viewers to Castle's father.

Finally, look for a Valentine's Day hour that centers around Ryan and Jenny's wedding.

Castle kicks off season four on September 19.