I spent two hours thinking about the position and I came to the following conclusion:
a) 1...Qxe7 2.Rxc8+ Rxc8 3.Qxc8+ +-.
b) 1...Kxe7 This variant took me a long time to find. I saw 2.Qb4+! (Most books indicate the move 2.Re1+
But could not find a satisfactory variant. The line continue 2...Kd6 3.Qb4+! The move that I was looking for 3...Kc7 4.Ne6+ Kb8 5.Qf4+ +-) 2...Qd6 3.Qxb7+! Qd7 (3...Ke8,3...Kd8 and 3...Kf8 lose) 4.Re1+ Kd8 or e6 5.Nf7+ +-.
But looking at what was played in the game, I was amazed. The game was: 1.Rxe7+! Kf8!
Bardeleben finds a magnificent defense, but Steinitz finds an incredible attack. 2.Rf7+! Kg8 3.Rg7+! Kh8 4.Rxh7+! Bardeleben resigns.Here Steinitz had mate in 10: 4...Kg8 5.Rg7+! Kh8 6.Qh4+ Kxg7 7.Qxh7+ Kf8 8.Qh8+ Ke7 9.Qg7+ Ke8 10.Qg8+ Ke7 11.Qf7+ Kd8 12.Qf8+ Qe8 13.Nf7+ Kd7 14.Qd6++.