The movie encompasses 4 Halloween horror stories which all have one thing in common: a mysterious kid called Sam, showing up in shabby pyjamas and a sack on his had whenever Halloween tradition gets broken. The film starts with a scene of Emma removing Halloween decorations from her yard, which you're not supposed to do before midnight, and as the result is covered by a sheet and gets her throat cut by candy sucker.
One of the stories features Charlie steal a bucket of candy sitting under the sign "please take one", when Mr. Wilkins, his school principal and the owner of the house catches him. Having eaten a poisoned chocolate Charlie vomits blood and dies, after which Wilkins dumps his body in the hole in his back yard (where, incidentally, another kid's body already lies). During this time Wilkins' son Billy keeps asking his dad to help him out with his jack-o'-lantern. This is where Charlie's severed head comes in useful...
The second story follows a small group of trick-or-treaters as they visit a query which is supposed to the site of the Halloween School Bus Massacre. Apparently 30 years ago, a bus driving 8 mentally challenged kids was intentionally driven into the lake, and having drowned, their bodies were never found. At the query teens organise a prank featuring water-drenched figures, after which a jack-o'-lantern thrown into the lake actually makes eight dead kids rise up.
Next in line is the story about Kreeg who scares trick-or-treaters away and steals their candy. Having his house filled with jack-o'-lanterns and trick-or-treat rhymes, Kreeg gets attacked by the pyjamas-wearing kid, Sam. During the struggle Kreeg manages to remove the sack from Sam's head only to reveal something between a jack-o'-lantern and a human skull. Finally Sam leaves chewing on a chocolate bar, and thanks to photos burning in the fireplace, we learn that Kreeg was the bus driver from the School Bus Massacre. We'll not disclose the fourth story nor the ending so there’s still a surprise or two waiting should you choose to watch this famous Halloween movie.