He's lost.
He got to Ardglass, ran through the buffers, down the pier and into the sea. The train floated up at Greenore, was winched ashore, but someomne had left the brakes off, so - boom! She's off to Amiens Street. It seems that a quick-thinking signalman at Clogherhead Junction switched the points, thus avoiding a little bit of a mess at Amiens Street.