From a fantasy novel in progress, currently at 92,800 words:
"It's solid, my Lord," said the soldier, turning from the heavy double doors to his master.
"Well, let's try the easy way first," said Lord Bormton.
He pulled something from a pocket and whispered to it. Those around him shied back as a misty form rose from the unseen object.
"Go in there. Drive them out. Do not kill or seriously injure them."
"Yes, Lord Bormton," said the thing, in a voice as insubstantial as its appearance.
The mist lost its definition and flowed to the doors, then through the tiny gap between them.
There was a pause. Then they heard, distinctly, "Oh, balls!" in the demon's voice, followed immediately by an unholy shriek.
Then all was silent again.
"Well, it appears we need to try something more difficult," said Lord Bormton, dissembling.
He was nonplussed, and distressed over losing that bound servant, but managed to give the impression the setback was minor and unsurprising.
* * *
"I think that's the fastest I've ever seen a demon driven off," said Bergen, smirking.
"It was a minor Aerial, the sort of thing normally used for spying or poisoning," said Llewellyn, keeping an eye on the door while his familiar, Grey, watched the stove pipe. "They're good at getting through wards and passing unnoticed, but not very formidable otherwise. Whoever sent it was powerful, though, to have it ready to hand like that. We must be on our guard."