Ser-h#7
Lion* b8
1. LIb8-b3 2. LIb3-g8 3. b4-b3 4. b3*a2 5. a2-a1=LI 6. LIa1-g7 7. d4-d3 Ra4-h4 #
* The Lion moves along Queen lines over another unit of either color to any square beyond that unit. A capture may be made on arrival, but the hurdle is not affected.