From non-existent, unknown or hidden resources(adverb)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "out of thin air" in a sentence
"Especially since I might see the people who now lived in my house—that “lovely” family that Mrs. Balicki the realtor had so conveniently produced out of thin air and had telephoned us about the night we finally came back from our joy ride with the Conways."
"He was convinced that Siuan Sanche had not been deposed at all, that al'Thor was insane and dying, that Tar Valon had murdered King Galldrian to deliberately set off the civil war in Cairhien, and that these three "facts" were somehow tied into those ridiculous rumors, always from somewhere conveniently far away, of people bursting into flame or nightmares leaping out of thin air and slaughtering whole villages."