Metallica

Metallica is a door nobody has walked through. The clerk knows the way here but has not been behind the counter for them yet: the first thread pulled from Metallica digs their records, covers and songwriters from MusicBrainz, which takes about half a minute, and every thread after that is instant.

Once dug, Metallica gets a page of their own at this address, and the ticket on the map fills in.