Yeah it felt like I was missing one for both, Venice was hard enough to remember it was so long ago. >_<' 

I know the Slitheen came back again for Summer and Ten, that was when they went to the present. Ish. 

I know we wanted to do:

Nine x Jen:

Berlin
42
Beast Below

Ten x Summer

Christmas with her parents
Shakespeare

I know we wanted them to switch bodies for another "fun finale" as well as do a timeskip where both Jen and Summer were young and the Doctors go back and meet them, do something important for them. And then we did want to do a crossover. But I forget with what? Or rather, why. I know we had a really good reason for bringing them together too. Oh I think we both wanted to do 42 with Nine and Ten and then somehow it would sort of mirror both events and that would make the dimensions collide...or something like that?