Time TunnelSeries Episode Number: 89
First Broadcast: Tue 31 Mar 2015 - ~8:00pm UTC (United Kingdom)
Running Time: 31 minutes 46 seconds
Recorded on Mon 27 Oct 2014 in The Moat Studios
Reports are coming in to UNIT of trains emerging from a railway tunnel in Sussex, their passengers and drivers dead. The Doctor elects to drive a train through the tunnel himself, but when he emerges Jo sees to her horror that he is covered in ice. Something in the tunnel has driven him close to the point of death. What can it be?