Just how the Germans progressed so fast that by noon on October 24 they
had a machine-gun posted on the square in Caporetto still remains, eight
days later, incompletely explained. All that is really known is this: at
2 a.m. they started a very violent bombardment. When the shelling
suddenly stopped after only two hours, the Italians regarded the
interruption merely as a lull, for the artillery preparation for an
infantry attack in force usually lasts much longer. With the valley
hidden by darkness, mist, and rain, and seeing more dimly than usual
through the mica of their gas-masks, the Italians knew nothing of the
German infantry's advance up the valley from the Santa Lucia bridgehead,
south of Tolmino, until the enemy had actually reached their wire. In
this way the Plec line of defense across that reach of the Isonzo known
as the Conca di Plezzo, a line specially designed to check an offensive
from Santa Lucia, was captured by surprise, and then German troops
poured down into the river gorge from Mrzli on its eastern side, until
the valley was full of the enemy, and Monte Nero and the other Italian
outpost positions on the heights beyond the Isonzo were completely
surrounded.

[Sidenote: Violent fighting on the Bainsizza plateau.]

The valley being in their possession, the Germans wasted no time.
Pushing northward along the river, one detachment occupied Idersko and
Caporetto; another proceeded to assault the height of Starijok, just
above Caporetto; yet another strong force made a frontal attack on the
ridge of Zagradan, which runs like a wall along the Italian side of the
river, and after fierce fighting took Luico, one of the pivots of the
defenses upon it. Elsewhere he had attacked at the same time with less
definite result. Mount Globocak was seized by surprise. It was an