not in; went off to somewhere else temporarily; to go away for a short period; to go off for a moment, usually to go and do something else or to leave someone (or a scene / situation / circumstance) temporarily, with an intention to come back
I'm so happy today! I joined a lucky draw this afternoon and waited for calling the numbers. When it came to the third prize, the person wasn't there and it became my turn after the second draw, how fortunate!