Opening a File
Helen Courtney-Teresa Sheehan
New Zealand Woman's Championship 1998
1... ♞g3+ 2. ♔g1
2... ♞h3+ 3. gxh3
3... ♞e2+ 26. ♔h1 ♛g1#
If white on move 2 plays 2.hxg3
then 2... ♜h6+ 3. ♔g1 ♛xg3
mate in three.
e.g. 4. ♖fd2 ♞h3+ 5 ♔h1 ♞f2+ 6. ♔g1 ♜h1#