I personally think it makes more sense if you guys come up with a reason for your characters to be in the same place at the same time instead of chasing after Nova or members of Nova. Chasing them puts you in direct conflict with them and it's just weird when you all of a sudden pull a one eighty and decide to work with them instead. I don't know what the context of the next mission will be, but if I were in your position I would figure out what it is and come up with a reason for your characters to be there. Only because introducing your character now will likely feel like a bit of a rush job.
But that's just what I would want to do.