Much like Santa Claus, James May has spent the year in his workshop getting ready for Christmas, in a festive special in which he reassembles his favourite childhood Christmas present.

But this isn't just any Christmas present, this is the one that changed his life and sent him on to a path of mechanical intrigue and reassembly. This is the Hornby Flying Scotsman with realistic chuffing sounds which James ripped open on Christmas Day 1972.

Laid out in all its 138 tiny component parts, James lovingly reassembles the train as well as his memories of Christmases and toys past. From the exhilarating remagnetising of the motor's magnets to some thrilling wheel-quartering amidst a backdrop of James's continued bafflement of electricity, we watch as James rebuilds the entire train set and hopes at the end his Christmas wish will come true and the train will start up and realistically chuff into the night.