[DoktorWho]

Thank you for version 2. Very impressive body of work. However I am right in the middle of version one.
Does this mean I must start again?
Or can I install v.2 over v.1 and contiue the campaign?
I've stopped this great campaign in case I mess things up if I install "2" over "1" - Can anybody shed a little light here? Thanks in advance. DW