The mutual captures of Black&White-Qs. 

1.S3e4!  

1.S5e4? Qb2+! 2.Kg8 Qa2!! 3.Qg6+ Kf3 4.Qh5+ Ke3= (4...Kg2? 5.Qh1#)  

1…Qb2+ 2.Kg6! 

2.Kh7? Qb7+ 3.Kh6 (3.Kg6 Se7+=) 3...Qb6 4.Sf6+ Kf5= 

2...Sf4+ 3.Kh7! 

3.Kh6? Qh2+ 4.Kg7 Sh5+= 

3...Qh2+ 4.Kg8! 

4.Kg7? Sh5+= 

4...Qa2+ 5.Kg7! 

5.Sf7? Qa8+=;

5.Kh7? Qh2+ 6.Kg8 loss of time 

5...Qb2+ 

5...Qa1+ 6.Kh7 Qa7+ (6...Qh1+ 7.Kg8+-) 7.Kh6+- 

6.Kf8! 

6.Kh6? Qh2+ 7.Kg7 Sh5+=;

6.Kg8? Qa2+ 7.Kg7 loss of time 

6...Qe5!!  

6...Qh8+ 7.Kf7 Qh5+ 8.Ke7+-

7.Qd1+! 

7.Qxe5? 7...Sg6+= 

7.Sf6+? Kf5!= (7...Kxg5? 8.Qxe5++-)  

7...Kf5 8.Sd6+ 

8.Qd7+? Se6+= 

8...Kxg5

8...Kf6 9.Sge4+!

9.Sgf7? Se6+! (9...Sg6+? 10.Kg8 Se7+ 11.Kh7 Qh2+ 12.Sh6+-) 10.Ke8 Sg7+ 11.Kd7 Qe6+ 12.Kd8 Qe7+ 13.Kc8 Qe6+ 14.Kb8 Sf5 15.Qa1+ Ke7=

9...Ke6 10.Qb3++- 

9.Sf7+ +-