With Oldmere retaken and Merridale in sight once more, General Percival was keen to keep the momentum going in the latest offensive on Alphe. With this in mind he moved the Librian 50th armoured to the North of the settlement while the corridor to Oldmere was still open.

On 2007.009M42 the Librian mechanised infantry of the 122nd regiment began their advance on the city, supported by the tanks of the 50th armoured and several Baneblade heavy tanks. In addition for the first time Librian airborne units were deployed in theatre. These Librian formations were veterans of several campaigns, and soon proved their worth as they advanced on Merridale.

The crucial battle developed around the main bridge over the river Amber which ran to the south of Merridale. Colonel Davidson had made contact with Traitor units of the Catechism to the north of the city, but chose to encircle the settlement. The commander of the Catechism clearly understood the significance of this move, deployed his strongest forces along the river and prepared a counter attack.

The battle became fierce as traitor marines were deployed against the mechanised infantry on a bend on the Amber river at dawn on 2207.009M42. On Davidson's left flank, fast moving Devil Dog flame tanks supporting his mechanised infantry scored successes against traitor Rhinos, while the infantry of the 122nd were involved in heavy fighting against elite marine formations. The 122nd took heavy casualties as the morning rose, the Catechism reinforcing this flank with Obliterator constructions, dreadnoughts and a daemon prince of Nurgle.

In the centre the Librians knew they had to get across the river, where traitor troops had taken up a reverse slope position on the south bank. On Davidson's right the heavy tanks of the 50th armoured, supported by Baneblade super heavy tanks duelled over open boggy ground with Catechism Vindicators.

As the 22nd wore on the Imperium forces achieved good success on the right, destroying the Chaos forces and turning the Catechism flank. In the centre the forces of Chaos were also buckling, and although one Baneblade was destroyed on the right, with no loss to the Chaos tank formations, the Catechism were losing their footsoldiers. Terrible casualties were inflicted by accurate Leman Russ and Baneblade fire, while the Devil Dogs on the left flank were equally destructive. In contrast the Chaos obliterators, teleported into good firing positions, were woeful, being destroyed for no Chaos gain.

By mid afternoon on the same day Davidson knew the Chaos forces were finished. At one point it was touch and go, with the Chaos forces, though taking severe casualties, still holding key objectives on the river. However as the day wore on and the first elements of the Librian airborne arrived, it became clear that the Catechism would nopt be able to hold their positions on the Amber river without being wiped out. The battle now became a fighting withdrawal.

Merridale was now open, and the remaining Catechism formations in the city were annihilated as Moonface's elite troops withrew south. By the 26th the area to the south of Merridale had been cleared, and the inquisition were pouring over the city which had been occupied since 2505.009M42, rooting out corruption where it had taken hold and cleansing the city. This cleansing cost Merridale half its population. However the city had been retaken and the momentum kept up. The Catechism was now on the back foot and taking heavy casualties. How long could they sustain the Alphe campaign?