I have a Cambridge to London Terminals season ticket. When the options were LST or KGX it was easy but the new Brighton service calling at STP and LBG has complicated matters. In some circumstances Cambridge to London Bridge is my best option but the ticket office tells me my season ticket is only valid as far as St Pancras. I don’t want to get a specific LBG season ticket as the flexibility of having KGX/Northern Line or LST/Overground is very helpful. I have an Oyster Card but obviously there is no way to touch it in passing through STP on my way to LBG or back and I want to avoid the long ticket queues to buy an STP to LBG ticket before I travel. A Cambridge - Z1-6 is almost 50% more expensive so not worth the extra cost. Is there any creative way round this or should I be resigned to just using KGX & LST ?