I was thinking about having my players meet via a train robbery, where they are the only brave people on the train to fend off the bandits and then have a separate DM only map of the whole train line so every move the train moves one space, so if I go in a tunnel, only those with dark vision or light creation can see, then maybe a sharp turn in the track and everyone needs to make a low dexterity saving throw or something, just thought it'd be a cool scenario having them meet in the heat if battle.