'General Hospital' spoilers for Oct. 31 – Nov. 4: A Halloween celebration turns into a nightmare; Sonny blows his top over a mistaken identity; Anna drops a bombshell

Port Charles experiences Halloween like no other, as it becomes filled with fear, horror and shock in this week’s episodes of “General Hospital” (“GH”). On Monday, Port Charles residents gamely put on their costumes for a big night at the Metro Court hotel. However, the party guests get the fright of their lives when an unexpected visitor arrives, causing quite a mayhem.

Spoilers suggest that the unwanted guest is Valentin (James Stuart), who goes there for a mission. Dante (Dominic Zamprogna) is not happy at all after seeing Valentin, which leads to a scuffle. Other “General Hospital” cast members who will appear on the upcoming episodes include Sonny (Maurice Benard), Franco (Roger Howarth), Jason (Billy Miller), Anna (Finola Hughes), Michael (Chad Duell), Nelle (Chloe Lanier), Griffin (Matt Cohen), Alexis (Nancy Grahn), Sam (Kelly Monaco), Curtis (Donnell Turner) Ava (Maura West), Liz (Rebecca Herbst), Nina (Michelle Stafford), Kiki (Hayley Erin), Dillon (Robert P Watkins) and Morgan (Bryan Craig).

Spoiler alert! This article contains "General Hospital" spoilers.

The show’s official website uploaded a preview video for the Oct. 31 episode. In the trailer, Liz accuses Franco, “You always have to assume the worst when I’m with Jason. Meanwhile, Nina asks Griffin how he knows Charlotte. Griffin reveals, “She’s my daughter.” Elsewhere, Dante aims a gun on Valentin. “I have a document in my pocket that will explain everything,” Valentin insists. Kiki, on the other hand, wonders what Dillon, dressed as Elvis, is doing at the party. Morgan wraps the trailer as he tells his dad, “I made it home to you.”

Soap She Knows reports that Tuesday’s installment deals with Anna’s new assignment, Michael’s interrogation of Nelle and Griffin’s plea for help from Anna.

On Wednesday, Alexis comes clean to Sam about her personal motives. Elsewhere, Curtis betrays Sam, while Franco finds it difficult to keep his jealousy in check.

Thursday’s run focuses on Nelle, as she makes a wrong interpretation of what she hears. Meanwhile, Jason presses Curtis to admit what he knows. Anna, on the other hand, feels like she already knows someone she has just met.

For its last salvo this week, “GH” features Ava as she gets ahold of a terrifying piece of information. Anna, meanwhile, shocks everyone with an announcement.

Find out what happens next on the "General Hospital" series, which airs in the US Mondays to Fridays on ABC Daytime. Stay tuned for more "General Hospital" spoilers.