Not P but Moby-Dick (110)

[Mike Jing]

>From Chapter 134:

Caught and twisted—corkscrewed in the mazes of the line, loose harpoons and
lances, with all their bristling barbs and points, came flashing and
dripping up to the chocks in the bows of Ahab’s boat. Only one thing could
be done. Seizing the boat-knife, he critically reached within—through—and
then, without—the rays of steel; dragged in the line beyond, passed it,
inboard, to the bowsman, and then, twice sundering the rope near the
chocks—dropped the intercepted fagot of steel into the sea; and was all
fast again.

What exactly is happening when it says "he critically reached
within—through—and then, without—the rays of steel"? Is it the same motion
as "twice sundering the rope near the chocks", or is it something else?

Also, does "was all fast again" mean the cut line was retied together?