White sacrifices a piece in the black kings's field and black pawn captures it self-blocking a flight.
See also: Active sacrifice.
Feather, Christopher John
Sinfonie Scacchistiche, U. Castellari MT, 1978
2nd Prize
1.Qh3
Se1
2.dxe1=R
Bg4#
1.Ra5
Rc1+
2.dxc1=R
Bb5#