1. Tb4+ cxb4 2. ??
Essential discovery: 
Every rook-move crossing b4 threatens with tempo 
(2. Db4+! cxb4 3. Txb4+! Kc5 4. Ld4+ Sxd4#)
However: 1. Tb3?/Tb2? fxe5! 1. Tb1? fxe5! [2. Db2 Tf3!]
1. Tb2? Kd4? 2. Db4+ c4, best 3. Dxc4+ Kxc4 4. Tb4+ etc. 

Solution:

1. a5!! Flight (2. Txc5+ Kxc5 3. Dxc7+! Kb5 4. Dc6+ Kxa5
5. Lc3+ Sxc3#)
1. - c6 Counterflight!
Thematic temptation: 
2. Tb1? fxe5!
Correct T/D-Bahnung, now two choices: 
2. Tb3! (3. Db4+ 4. Txb4+ Kc5 5. Ld4+ Sxd4#) fxe5
Reward: 
3. Tc3+ Kd4 
4. Dxe5+!! Kxe5 
5. Tc4+! S~# 
3. Lxe5? (4. Tc3+) Tf3!
2. Tb2? now Kd4! fxe5? 3. Sd6+ Kc3 4. Db3+ etc. 

Subtle non-standard classic. Two deeply hidden threatplays, each reaching over the full distance, open the "invisible" gates to a fulminant, breathtaking finale.   

Special hallmarks:
virtually La1 is forcing S# by active moves, in real play unmoved - as battery-rear-piece.
Manifold, flexible use of wR as the strategic mastermind.     

Theoretically, one could complain a "mate-dual", because
5. Tc4+ allows both 5. - Sc3# and 5. - Sd4#. But in truth this is a successful joke: 5. - Sc3 prevents 6. Tg4 by doublecheck and 5. - Sd4 prevents 6. Tg4 via knight-rook-Grimshaw!