Through the waist-deep slime the Tanks floundered, displacing tons of mud under the resistless pressure of the broad-flanged endless belts. A shell from a distant German gun burst close alongside one of the steel mammoths, converting the "invisible" colour-scheme into a hideous daub of greenish yellow, but beyond that the H.E. missiles had no effect upon the mobile fortress. Straight from the triple row of barbed wire the Tanks waddled deliberately and remorselessly. The Huns watched their approach with evident concern, so much so that the bombers engaged in a duel with the Wheatshires across the traverse abandoned the task and scurried to their dug-outs. A few, more courageous than their comrades, directed their energies towards hurling their missiles against their uncanny foes. It was like shooting peas at a crocodile. As matchwood the stout stakes supporting the entanglements snapped under the impact of the leading Tank's snout. Wire, coiling like writhing snakes directly the tension was released, was swept aside as easily as if made of pack thread. Then, lifting its bluff bows, the Tank ambled awkwardly up the parapet of the hostile lines, displacing sand-bags by the score, and finally coming to a standstill, like a steel Bridge of Sighs, across a canal of liquid mud with grey-coated Huns in place of gondolas. "She's bogged!" yelled Penfold. "No fear," retorted Alderhame. "She's just having a little rest. See, her wheels aren't moving." The Tank was making good use of the stop, whether forced or otherwise, for astride of the trench she opened a terrific fire, enfilading the Germans as they crowded, panic-stricken, in the limited space 'twixt parapet and parados. Up went scores of hands, but in vain. Mingled with those of the Huns who wished to surrender were several "die-hards," who with bullet and bomb tried in vain to find a vulnerable spot in the armour of their titanic antagonist. A few even scaled the side of the Tank and rained savage but ineffectual blows upon it with the butts of their rifles. The second and third Tanks were now grinding their way through the hostile parapet. One, bridging the trench, landed immediately over the entrance to a dug-out. The reinforced concrete, set upon a mud foundation, was unable to resist the strain of hundreds of tons deadweight. The fore part of the landship sank until its vertical axis was inclined at an angle of forty-five degrees. "She'll never get out of that," thought Setley, for the mere possibility of that mass of metal extricating itself from the chaos of mud and shattered concrete seemed out of the question. For perhaps five minutes the Tank remained in this ignominious position, the while spitting out flame from the muzzle of her guns, her tractor bands revolving uselessly since they found no resistance in the soft earth.