While trick-or-treating, Adam, Watch and Sally encounter a house with a carnival of costumed characters that seems to be in another dimension.

When Sally and Watch become vampires, Adam allies with a very surprising former vampire hunter to save his friends and the school from a clever 500-year-old bloodsucker.

Adam and Watch get trapped in The Mayor's head -- quite literally -- when they chase him down to find out why he warned off Laurel a few weeks ago.