He needs a vessel

"Would you like to take a seat in the living room?" the man asks, gesturing towards the open door.

Roger takes another nervous glance towards the corpses. Becky doesn't take her eyes off the man. "We're fine here, thanks," she says coldly.

"Very well. Then allow me to cut to the chase, as it were. You may call me the Butler, and I have an important request to make of the both of you." He reaches into his inner breast pocket.

Becky trains her gun on him instantly. "Freeze!" He doesn't move a muscle. "Bring it out slowly. No sudden movements!"

The Butler removes his hand from his jacket, bringing with it a glowing orb about the size of a softball. Roger can't fathom how he could keep that inside his coat without making a visible lump.

"What is that?" Becky interrogates.

"What you see here," he says calmly, "is the soul of the late Master Sebastian Carmine."

"Are you crazy?!" Roger asks hysterically.

"Quite sane," the Butler says simply, "but I understand your scepticism. The majority of human civilisation has still yet to encounter tangible proof of the soul's existence. The other guests exhibited similar disbelief, but they seemed somewhat more convinced after we did this."

Before the couple can react, the Butler tightens his grip on the 'soul', making it glow more intensely. Becky and Roger's feet are lifted off the ground by an invisible ****. They are jolted up quickly until they are left levitating about two feet off the ground.

"Wha- wha- wha- whoooaaa!" Roger screams and flails.

"H-hey!" Becky yells. "Let us down, or I'll shoot!"

The Butler flicks his wrist, and the gun is wrenched out of Becky's hand and flung onto the upper landing.

"There is no need for concern," he says calmly. "This is simply a demonstration. A soul free of its body is able to influence the world in many supernatural ways, so I hope this serves as enough to convince you to put your doubt of the paranormal aside."

The couple are lowered gently to the ground. They stand shakily, clinging to each other for support.

"Say we believe you," Becky posits. "What then? What do you want from us?"

"Master Carmine's body has expired, but the world still has need of him." He bows at a perfect ninety degrees. "I humbly request the use of one of your bodies as a new vessel for the Master's soul."

"What?!" they both exclaim in unison.

The Butler stands back upright. "Worry not; your own souls shall not be lost. I wish to move both of your souls into one of your bodies, and use the vacated body to tether Master Carmine to this world once more."

"You are crazy!" Roger yells. "Why would we go along with that?!"

"If you comply with this request, you will receive half of Master Carmine's entire material wealth, as gratitude." The Butler pauses for just a moment, glancing into the living room then back to the couple. "However, if you refuse, then I shall be compelled to kill you both. With two more sacrifices, we can requisition a demonic body from the Underworld. This is not Master Carmine's preferred solution, but it is a backup plan he was willing to undergo if all else failed."

Becky and Roger both look nervously at the bodies piled up in the living room. When they look back to the Butler, Becky's gun is in his hand, pointed directly at them.

"I must insist on an answer, I'm afraid. The Master's soul cannot cling to this world in this form for much longer, I fear."