Original: 2tph all stations to Tring 1tph to Milton Keynes 1tph to Northampton, via Milton Keynes 1tph to Birmingham New Street, via Northampton 1tph to Crewe, via Northampton, the Trent Valley, and Stoke.
Simplified: 2tph to Birmingham New Street, Northampton via Watford, Tring, Hemel Hempstead and Milton Keynes 1tph to Crewe via Nuneaton.