Similar happened to me last night.
I let all the dogs out about 10 to do their last P & P for the night, 2 came back, no sign of Allez.

So started the Michelin man routine - socks, wellies, duvet jacket, woolly hat, two pairs of gloves, and went out to call him. Still no response to whistle or voice so I panicked - he MUST have got out somehow - trudged back to the gate, up the drive, across the lane, calling and whistling, almost crying,

freezing fog, road next to me with iced up cars crawling along it, easy access onto the railway line (although very few coal trains just now) Absolutely nothing for about 25 minutes, started to cry (well you imagine all sorts of things in those circumstances don't you?)- then I happened to sense rather than see or hear anything, looked down and there he was standing right next to me but on the other side of the fence. I SWEAR he was laughing!

I KNOW my front paddock is secure, other than possibly the gates under the bridge having fallen down, but he didn't come back wet so................ guess he was just hiding! A dog with a sense of humour?