I know I need the 2nd letter, but you also said the clue hinted at the line number, and I could not see any number hint but 'second,' so thought it referred to both things.
Googling Glend to check I'd got the name of Nan's sword right, I found a link to a Downs thread on obscure characters. I think it mentions some giants:
http://forum.barrowdowns.com/showthread.php?t=18935
I might read it after rechecking the L.O.B.