A friend is travelling tomorrow on a St Pancras to Brighton Super Off Peak Single (Route: Not Underground). As the Thameslink service is only hourly come mid afternoon to Three Bridges and there is a rail replacement bus Three Bridges to Brighton, is there any ticket acceptance in place? I have to admit the provision of information on this one is limited by GTR. I am wondering if the ticket will also be valid on London Underground to Victoria and also from Victoria on Southern services from there to Three Bridges under the circumstances. One journey an hour option is not much at all. He is arriving at Euston on a ticket that is only valid as far as Euston.