Erin goes and opens the front door to see Sherlock Holmes and Irene Adler. "Come in you two. Your costumes look wonderful."

"Where's Antony, Cleopatra?" J.J. asks cheekily.

"He's in the kitchen finishing off the hot appetizers. He shouldn't be long. Can I get you a drink while we're waiting for everyone else? I made punch and there's wine as well." Erin asks J.J. and Reid.

"I'll have punch, please." Reid says politely. He's not totally comfortable with Erin yet.

"I'll have white wine." J.J. can't believe the dress that Erin is wearing.

"Have a seat and I'll be right back with your drinks." Erin smiles at Dave's colleagues. She pours a glass of wine for J.J. and serves up two glasses of orange punch for Reid and herself. She carries a tray over and sets it down in front of J.J. and Reid. The doorbell rings again and when she answers the door Batman and Poison Ivy are on the doorstep. "Come in. You two look fabulous. Very nice Penelope."

"Thank you, Erin. I made it myself." Penelope tells Erin. She's proud of her sewing skills.

"I had a friend make my costume. Can I get you a drink?" Erin asks Derek and Penelope.

"Derek drinks beer and Penelope always has a fruit based drink!" Dave calls from the kitchen.

"Thanks Marc Antony!" Erin calls back teasingly.

"Beer's in the fridge!" Dave reminds Erin. "In case Her Royal Highness wants to get drinks herself."

"Very funny! Just bring a beer out when you come! I'll pour Penelope a daiquiri. Cleopatra can't be expected to do everything herself." Erin teases Dave.

"Okay, I'll be right out. Everything's just about ready. Who are we still waiting for? It's not a party without everyone." Dave asks.

"We're still waiting for Beth and Aaron and Alex and James. Can I get you a drink, Antony?" Erin asks as she leans against the doorjamb to the kitchen.

"I'll have a glass of red wine if you're pouring, my lovely Cleopatra." Dave kisses Erin's cheek.

"I thought you would say that. Here you are, sweetheart." Erin hands Dave a glass of his favourite red wine.

"Thank you, sweetheart." Dave takes the wine from Erin and grabs a beer from the fridge for Derek. He walks out into the living room.

Derek wolf whistles when he sees Dave in his toga. "Dude, Hotch was right! You do have fantastic legs for a guy. How lucky is Erin?"

"Why is Hotch talking to you about my legs? Just because Hotch is my normal roommate on trips doesn't mean he gets to give away all my secrets all at once." Dave grumbles.

"Oh, but it's so much fun to tell your secrets, besides I knew one day you would wear a Hallowe'en costume that would show off your legs so I would have an excuse to tell everyone about your fabulous legs." Aaron teases Dave when he walks into the party.

"Very funny Captain Von Trapp. I've got better legs than you do." Dave goes over and hugs Aaron. "You and Beth look great."

"Well, you and Erin make a great Antony and Cleopatra. In fact, I'm impressed with all your costumes." Aaron says as he looks around the room. "Where are Alex and her husband?"

"Not here yet. Can I get you two a drink?" Dave asks being a good host.

"I'll have a beer, Dave." Aaron sits down with Derek and Reid.

"What about you, Beth? We've got just about everything around here." Dave asks the other newest member of the family.

"I'll have a white wine. Thanks, Dave. You have the best parties all the time, or so I've heard." Beth teases Dave.

"The parties here do tend to be legendary. Let's just relax and enjoy tonight. We'll kick this party off when Alex and James arrive." Dave sips his red wine and watches Erin interact with the other women."