into thin air
US /ˈɪntu θɪn ɛr/
UK /ˈɪntu θɪn ɛr/

1.
凭空, 无影无踪
disappearing completely and mysteriously
:
•
The magician made the rabbit vanish into thin air.
魔术师让兔子凭空消失了。
•
All our plans for the trip vanished into thin air when the airline cancelled our flight.
当航空公司取消我们的航班时,我们所有的旅行计划都凭空消失了。