Taking the train? Why not fly? ‘Passengers,’ the newest touring production to open at The Old Globe and a manifestation of Montreal-based troupe Les 7 Doigts De La Main (The 7 Fingers), is perhaps, as a technicality, theatre, but in actuality much more than that. It is dance, song, movement, and acrobatics. There is a script yet the show demands a degree of improv to accommodate the sheer level of physicality that the performers imbue in their work. They are audacious, fearless, and evocative. And yet, despite the complexity, the show is simple in its premise, presenting a cadre of scenarios that happen when we are passengers – together – on the train…