I have a ticket (see below for the actual ticket) on a weekend, and intend to use it to travel from St Pancras to Brighton and back. It says that it is not valid on the London Underground.
Can I use it on the Overground to travel from an Overground station to Euston, transfer to St Pancras and continue my day journey, then return to St Pancras in the evening and use the return ticket to travel from Euston to another Overground station?