After the initial anticipation of great results for the Allied offensive that opened on 1 July, the French and the British had to consider their next moves. Haig made the fateful decision to reinforce perceived success at the center and south of the British line (although Joffre, rightly, wished to continue the pressure at Thiepval).

The result was a series of minor (if expensive) operations to provide a suitable base line for the next major British assault along the Bazentin Ridge, running approximately from east of Longueval to west of Bazentin le Petit Wood. Thus Ovillers, Mametz Wood and Trônes Wood became prominent in Britain's military history.

The French soon began to appreciate that the great success south of the river on 1 July was not going to achieve much more unless the front was extended southwards (impractical, given pressure at Verdun and limited manpower resources); or if advances could be made north of the river that would outflank the Germans to the south.

Meanwhile Falkenhayn continued to believe in the imminence of British offensive action further north, in French Flanders, despite the fact that he was reassured time and again that there was no evidence for this and that in any case such an eventuality could be contained with reduced resources. Eventually the offensive in Verdun was halted, in late August Falkenhayn was removed after he had presided over increasing friction at the highest level on the Somme front amongst senior commanders; Ludendorff and Hindenburg took over and the genius of German defensive measures, Loßberg, arrived on the scene.

This book covers actions at Ovillers, Pozières (notably involving the Australians) Mametz, Delville Wood (South Africa's first great war time action in Europe), the bitter fighting at High Wood, all leading up to the great attack on the Somme on 15 September. This was the third such major effort by the British army and the first time since 1 July that the Allies had attacked simultaneously in strength.

The book then looks at aspects of the fighting associated with this attack, in particular the role of the New Zealand Division and of the Guards Division around Les Boeufs. It then concentrates on the Anglo French boundary area (Guillemont and Combles) before considering French activity at Maurepas, Cléry, Biaches and La Maisonette and the extension of the French front on 3 September, with fighting at Soyécourt, Lihons and Vermandovillers.

The book ends with a review of the situation both sides found themselves in mid September, before the action continued its relentless grind at extraordinary cost in men and materiel.