Disappear, etc. into thin air - Idioms by The Free Dictionary
disappear, etc. into thin air
disappear into thin air
To vanish completely and without a trace. I would give you my stapler, but it seems to have disappeared into thin air.
disappear, etc. into thin ˈair disappear, etc. suddenly and in a mysterious way: The money vanished into thin air. Nobody knows what happened to it.