This is an excellent episode. The only reason that I gave this 9 Stars, is because I believe this should have been at least a 2-Part episode (maybe even a 3-Part). More time should have been given to the chase. More time should have been given to the main theme of explaining how so many different alien species look similar all across the galaxy. The realization that all Humanoid life was seeded throughout the galaxy & descended from this one ancient alien civilization deserved more time too. Even combining both TNG & DS9 crews could have given this idea an even bigger canvas to work with. Also, I think more alien species should have been in on the chase too (Andorians, Ferengi, Orions, Vulcans, etc). Either way, this was still a very good episode & gave us some great character developing moments from Picard too. This was, also, well executed by Jonathan Frakes at the helm too.