Page 7

The minesweeper grid on this page solves as:

.	.	.	.	.	.	.	.
.	.	⚑	2	2	.	.	.
⚑	2	3	⚑	.	⚑	.	.
.	2	.	⚑	.	.	2	.
⚑	1	.	1	1	.	⚑	.
.	.	.	.	.	2	.	.
.	.	.	2	⚑	2	.	.
.	.	.	.	⚑	.	.	.

Superimposing this grid onto the letters in front of the map on Page 6 puts the mines above the letters "GYAGOPHER" which anagrams to GEOGRAPHY.

[The joint explosion of the mines at Messines in 1917 ranks among the largest non-nuclear explosions of all time. The evening before the attack, General Sir Charles Harington, Chief of Staff of the Second Army (General Sir Herbert Plumer), remarked to the press, "Gentlemen, I don’t know whether we are going to make history tomorrow, but at any rate we shall change geography". The solution to this Minesweeper puzzle seems to reference Harington's remark.]