Paris Stories in Assassin's Creed Unity (ACU).

The Paris Stories are a variety of short missions of only a few objectives. Arno Dorian helps various people. They become available as early as Sequence 2. Waiting until Sequence 4 for the Phantom Blade makes a number of these missions a lot easier. If you wait until Sequence 10 then any of the Paris Stories can be completed with access to Arno's full range of skills.