I just re-watched “Apple Red as Blood”, and noticed that when Regina was talking to Jefferson and dropped Daniel’s ring in the hat, Jefferson told her she needed to “Direct me to the time and place where this object is.”
If she can direct the hat to a specific time, as we saw in the episode (when a portal opened up the moment the apple rolled down the hill, after SW ate it), is time travel possible? What would have happened if Regina had access to more magic, and she went into FTL at that time?