The Metropolitan Line’s Uxbridge branch passes through Rayners Lane: the station is where the Metropolitan and Piccadilly Lines meet.  The new Metropolitan Line trains were introduced in 2010 so Timothy is familiar with both them and their predecessors.

The new trains are the first on the Underground to have air conditioning and walk-through carriages. It took a little getting used to, but Timothy is now a dab hand at walking through the length of a train: walking around all the rails and stepping gingerly on the turning metal plates between the carriages is now second nature.