On a train to Tring, presumably usually a Black Five working.

Peter Kerslake says "A notable visitor to London's Broad Street station 70004 William Shakespeare was at the date of this picture allocated to Willesden depot, its glory days working the Southern Region's "Golden Arrow" now just a memory.
A transfer away from Willesden to Carlisle's two depots in May 1963 was followed by a return to Willesden again in July 1963 before it left again in January 1965 for Crewe, Stockport and Carlisle, ending its days from Carlisle Kingmoor in December 1967."
Photo by, and copyright of David P Williams