These were very briefly the two alternative possibilities which G.H.Q. had to face, and the problem awaiting solution was how to provide with the inadequate force at its disposal for the efficient defence of its lines no matter where the blow might fall. The matter was further complicated. The French were equally nervous of a sudden blow against their weak spots in Champagne and at Rheims, which might lay open the German road to Paris, and this fear rendered it impossible for them to place at the disposal of British G.H.Q. sufficient forces to make up the very grave inequality of strength which existed on the British front. The grouping of forces was, moreover, rendered more difficult by the fact that, so great were the available German reserves, it might well prove that the first enemy blow, although serious and energetic, might in reality not be the main effort. This doubt would inevitably, whatever the Allies' dispositions might be, have the effect of sterilising the British and French reserves for some days until it was quite certain that the first blow was not a feint, to be succeeded later by a still greater effort elsewhere. Such was the problem, and surely never has a military commander been faced by a more difficult situation; for on the wisdom of G.H.Q.'s dispositions would probably rest the fortunes of the whole British Empire. Before stating the solution adopted by G.H.Q. in especial relation to the doings of the 2/4th Battalion, we may perhaps be pardoned for glancing at one or two aspects of Ludendorff's problem which, as is now known from his own book, was by no means free from difficulty.