11. For a small isolated post and an active enemy, there are no _flanks_, no _rear_, or, to put it otherwise, it is _front all round_. 12. Beware of being taken in _reverse_; take care, when placing and making your defences, that when you are engaged in shooting the enemy to the front of your trench, his pal cannot sneak up and shoot you in the back. 13. Beware of being _enfiladed_. It is nasty from one flank--far worse from both flanks. Remember, also, that though you may arrange matters so that you cannot be enfiladed by rifle-fire, yet you may be open to it from long range, by means of gun or pompom fire. There are few straight trenches that cannot be enfiladed from somewhere, if the enemy can only get there. You can sometimes prevent being enfiladed by so placing your trench that no one can get into prolongation of it to fire down it, or you can "wiggle" it about in many ways, so that it is not straight, or make "traverses" across it, or dig separate trenches for every two or three men. 14. Do not have your trench near rising ground over which you cannot see, and which you cannot hold. 15. Do not huddle all your men together in a small trench like sheep in a pen. Give them air. 16. As once before--cover from sight is often worth more than cover from bullets. For close shooting from a non-concealed trench, _head cover_ with _loopholes_ is an advantage. This should be bullet-proof and not be conspicuously on the top of the parapet, so as to draw fire, or it will be far more dangerous than having none. 17. To surprise the enemy is a great advantage. 18. If you wish to obtain this advantage, _conceal_ your position. Though for promotion it may be sound to advertise your position, for defence it is not. 19. To test the concealment or otherwise of your position, look at it from the enemy's point of view. FIFTH DREAM. "A trifling sum of misery New added to the foot of thy account." DRYDEN. "Jack Frost looked forth one still clear night, And he said, 'Now I shall be out of sight; So over the valley and over the height In silence I'll take my way.'" GOULD. Again I faced the same task with a fresh mind and fresh hopes, all that remained with me of my former attempts being _nineteen_ lessons. Having detailed the two patrols and the guard on Waschout Hill as already described, I spent some twenty minutes--whilst the stores, etc., were being arranged--in walking about to choose a position to hold in the light of my nineteen lessons.