We'll be arriving by train at Gare du Nord and will not be checking in to our apartment in Montmartre until after 10pm. Should we stay around Gare du Nord, get a luggage locker, and do some exploring before taking a taxi to our apartment, or should we head over to Montmartre straight away? If we do head to Montmartre immediately, what are some options for stowing our luggage? Can we ask a hotel that we are not staying in to hold it? Any advice would be greatly appreciated.