Episode 139 - The Mark of the Rani

The Doctor plans on taking Peri to the grand opening of Kew
Gardens but as per usual, things don't go exactly to plan and
they find themselves at the forefront of the struggle of the
industrial revolution. This week, Paddy and Tricia follow The
Doctor and Peri as they attempt to find out who is trying to
sabotage the next step in human progress. However, a couple of
old faces from The Doctor's past are also at play, planning to
dominate humanity with The Mark of the Rani.