Volatile Rubble

By Walk, in Tannhauser

Haven't seen a topic about this, so I'll post it myself. From the Operation Hinansho rulebook: "Once a volatile rubble token has been placed, the Volatile circle can no longer be activated. This circle is now treated as volatile rubble for the remainder of the game. This means any character that passes through this circle takes three automatic attack successes, in addition to the effects of rubble." The question here, of course, is the phrase "passes though." Does this mean enters? Exits? Ends their move on? Enters and exits in the same turn? The idea here would seem to be either that the rubble is still volatile and disturbing it causes a small explosion or that the rubble is on fire/superheated. These two ideas would both suggest different effects, so I'm honestly not sure. Does anyone have any ideas? Is there another instance where the phrase "passes through" is used in Tannhauser?