Speak the password and enter, if you dare

Question

Speak the password and enter, if you dare.

Can you find a logical path through the maze and explain why it is correct? What is the password?

Rules:

• must visit each square at least one time (or more)
• orthogonal movement only
• no immediate backtracking
• first names only

IN>agalewndromir
   zonromenoraro
   rodonelavoceb
   ?lahadrlebelr
   da?io?eegrami
   aggwemasogrin
   kanirryalero?
   lsarunavemond
   uthomnarnlguw
   loguamsadaada
   llidnellicnll
   uworarualegii
   myev?aegmothn
   anwesoisoronu
   rolduraluieet
   ?siuimhithnih>OUT

Answer 1

Phew, this took some perseverance! The route through the maze traces the following overlapping path:

To navigate it, we must trace out:

a chain of character names from the books of J.R.R. Tolkien, where the last letter of one name becomes the first letter of the next.

The characters who appear are (in order):

IN > Azog, Gandalf, Frodo, Oromë, Elenwë, Elrohir, Radagast, Tulkas, Saruman, Nellas, Smaug, Gollum, Manwë, Éowyn, Nori, Is(u)ldur, Rose, Eärendil, Lotho, Ori, Ingwion, Nerdanel, Landroval, Legolas, Sam, Merry, Yavanna, Arveleg, Gríma, Argeleb, Boromir, Rorimac, Celebrindor, Romendacil, Laura, Arvedui, Imrahil, Luthien, Niënor, Rosie, Egalmoth, Hilda, Angelica, Algund, Dwalin, Nuneth > OUT

(Letters in bold here are those which must replace the question marks.)

Which means the password - spelled out by the letters hidden behind the question marks, in the order we encounter them - is:

FRIEND, which is a reference to an event in Lord of the Rings where the West-door of Moria bears an inscription with the instruction to "speak 'friend' and enter" (hence the title here!). Once Gandalf does so, the gate opens!