he cannot move, because his K B P would then remain en prise. If he moved 26 ... K to Kt 2, defending Kt and P, White would win his Queen by playing either Kt to B 5: ch., &c., as pointed out after Black's 23rd move; he is consequently forced to move as in the text.

27.Q to K 3...

To prevent Black from playing 27.... R to Q 7, which would be a powerful move, as it would attack White's pawns on the Queen's side.

...27.Q to B 5 (?)
28.Kt (R 4) to B 5...

(The position being highly instructive, it is illustrated in Fig. 8. White sacrifices a piece on the chance of Black not seeing the right defence. In which case the subtle threat is as follows—

...28.P takes Kt
29.Kt takes P29.Kt to Kt sq.

Defending the threatened R P.

30.Q to Kt 3...

And wins, as the mate with Q to Kt 7 cannot be prevented.)

...28.P takes Kt
29.Kt takes P29.Kt to Kt sq.
30.Q to Kt 3...