This is part 2 of 3. Part 1 is here.
In locum igitur iuxta pontem, qui Marmoreus dicitur, pariter convenerunt, captantes iter, quo ad monasterium pervenirent. illis ergo ex una parte, et istis ex altera consistentibus, validior pugna inter utrosque coepit, dum adversae partis hostes invalidi redderentur. etenim non erat illis leve transitum habere per istos. lapidibus quippe vel quibuslibet armis ad manum inventis, pellebant procul tyrannos, condensa silva et artae rupes nostrorum sublevare lacertos.
non gelidus sanguis oppletos strinxerat thoros
nam valida pugna diem abbreviant ultra
quam hiis necesse, vel illis fuerat ferre.
vibrantur enses, iaciuntur spicula, vectes,
et duris dumis haerebant spolia furis.
quid diu moror referre crimina dira,
plebeia manus quae gessit fronte iniqua?
quidam enim ex servis sacri monasterii, videntes se immenso certamine fatigari, et quia, divina gratia protegente, nulla dabatur facultas hostibus transeundi, magisque tyrannorum acies acrius prosternebantur, dominos suos deserentes, clam se subduxerunt; illisque in acie derelictis, Saracenorum regem adierunt, et libertatem cum vita ab eo postulantes, maioris lucri victoriaeque potioris eventum se ferre posse dixerunt. mox ille gavisus, servorum animos donis aureis et mortiferis suasionibus oblectans, incitat explere promissa. sponsione ergo accepta, et inito foedere, mali malorum duces effecti, dominis illorum nescientibus, verso itinere pars maxima pugnatorum, subito ex adverso super sacrum monasterium irruerunt, eumque undique circumdantes ignibus combuserunt, sanctos etiam seniores, quos ibidem invenerunt, gladiis necaverunt. exstat igitur sanctorum sanguis monachorum pro Christo effusus, evidentia indicia hodieque demonstrans, illitis vel aspersis eiusdem ecclesiae parietum ac pavimentorum saxis ac lapidibus.
(John the Monk, Chronicon Vulturnense 1.363-364 Federici)
Thus they mustered at a spot near the Marble Bridge,* blocking the road that led to the monastery. They stood on one side [of the river] and their opponents on the other, and a fierce battle began between them. The enemy were left helpless on the opposite bank, for it was no easy matter to cross to the near side. Seizing stones and other sorts of weapons, they drove the tyrants some way back, while the dense woods and the walls assisted the courage of our men.
No icy blood constrained their powerful muscles
For they cut the day short by fierce fighting.
That makes it hard for both our men and the enemy to endure.
Swords are brandished, javelins and darts are thrown,
And the plunder of the thief sticks fast in the sharp thorns.
Why do I spend such a long time relating the dreadful crimes
That the hand of the vulgar has carried out with evil intent?
However, some of the serfs of the holy monastery, exhausted by this great battle, and seeing that through the protection of Divine grace no opportunity had been given for the enemy to cross [the river], but rather that the battle line of the enemy was being fiercely struck down, deserted their lords. They secretly sloped away, abandoning their lords in the midst of the fight. They went to the king of the Saracens, begging their lives and freedom from him, and saying that they could bring him a favorable otucome and the great rewards of victory. He immediately rejoiced, seducing the minds of the serfs with golden gifts and deadly promises. These promises were accepted and an agreement was made; and without the knowledge of their lords, these evil men acted as guides to the [other] evildoers. Going by a back route, a large party of warriors suddenly rushed into the monastery from the other side, and set light to it, setting fires on every side. They also put all the elders whom they found there to the sword. Thus the blood of these holy monks was shed for Christ. The marks [of this] are clear and can be seen today, having been smeared or sprinkled on the wall of the church, on the flagstones of the floor and on the stones.
* A bridge crossing the river Volturno, very near the complex of monastery buildings.
(tr. Graham Loud, with his note)