I’m going from Cheltenham to London tomorrow. There isn’t a direct train, so I have to change at Kamble. The train leaves Cheltenham at 8:35 from platform 2, and it gets to Kamble at 9:08. Then I have to catch the 9:18, which gets to London Paddington at 10:40. A single ticket costs £22, but I can get a return for £40 if I book in advance.