Diagram above: Black to move. What would you do?
Scroll down to see the solution.
Once we observe that the white king and queen is on the same diagonal, we naturally find that 1… Qh1+ will win the undefended white queen on a8.
Diagram above: 1… Qh1+ 2.Ke3 Qxa8. Black wins the white queen (worth 9 points in material).
This tactic became possible because black’s queen could exploit the fact that white’s king and queen are on the same diagonal and the white queen is undefended. Note that if the white queen were defended (say, for example, white had a knight on b6) then this skewer would not have been effective.