Puzzle of the week #111

Chess Diagram: 

[Event "Puzzle #111"][Date "2010.04.02"][Result "1-0"][SetUp "1"][FEN "2r1rbk1/1bq2ppp/pp1p4/4n1P1/Pn1BP1N1/2N3Q1/1PP2RBP/3R2K1 w - - 0 26"]26.Rdf1

Wikipedia has a short but impressive introduction for this famous chess player:
"Vasily Vasilyevich Smyslov (24 March 1921 – 27 March 2010) was a Soviet and Russian chess grandmaster, and was World Chess Champion from 1957 to 1958. He was a Candidate for the World Chess Championship on eight occasions (1948, 1950, 1953, 1956, 1959, 1965, 1983, and 1985). Smyslov was twice equal first at the Soviet Championship (1949, 1955), and his total of 17 Chess Olympiad medals won is an all-time record. In five European Team Championships, Smyslov won ten gold medals. He remained active and successful in competitive chess well into the 1960s and 1970s and he qualified for the finals of the World Championship Candidates' Matches as late as 1983. Despite failing eyesight, he remained active in the occasional composition of chess problems and studies until shortly before his death from heart failure."
Over such a long career he has played countless important games and here I don't mean just important for the result, but also for learning from them. The above position is from one of his games, the last move for white is shown. Your tasks:
a) Analyse the position and propose a plan for both sides (10 points)
b) What should Black respond: 26... Re7 or 26... Nxg4? (5 points)
c) Write the best line you can think of based on your response at question "b" (10 points)

Total available points for this puzzle is 25. The answers will be published next week together with puzzle #112.

Puzzle #110 solution:
This position was also from one of Smyslov's games, or more precisely the game Levenfish - Smyslov, USSR, 17th Ch 1949. Your responses were basically grouped in 2 different groups: those who saw the excellent sacrifice 22.Rxg6!! ... and those who missed it. It is also interesting to note White's first two moves of the combination 22.Rxg6 ... and 23.Rh3+ ... can be played in reverse order for the same result. Before posting the solution I would like to point out that Owen had by far the most complete response; congratulations!
Without any further ado, here is the combination as presented by Canadian GM Kevin Spraggett:

[Event "Puzzle #110"][Date "2010.03.25"][Result "1-0"][SetUp "1"][FEN "r1q2r1k/pp2ppb1/2p2np1/3P4/3BP3/1QR5/PP2NP1P/4K1R1 b - - 0 21"]21...Nxe4 22.Rxg6!! fxg6 {Now the diagonal "a2-g8" is open} (22...e5 23.Rh3+ Kg8 24.Bxe5 fxg6 25.dxc6+ Rf7 26.Bxg7 Qxh3 (26...Kxg7 27.Rh7+ Kxh7 28.Qxf7+ Kh8 29.cxb7 {White wins}) (26...Qxc6 27.Bd4 Nf6 28.Rh8+ Kxh8 29.Qxf7 {White wins})) 23.Rh3+ Kg8 24.dxc6+ e6 (24...Rf7 25.cxb7 Qc6 26.bxa8=Q+ Qxa8 27.Bxg7 Kxg7 28.Rh7+ {White wins}) 25.cxb7 Qc6 26.bxa8=Q Rxa8 27.Bxg7 Kxg7 28.Qe3 Nf6 29.Nd4 Qh1+ 30.Ke2 Qd5 31.Nxe6+ Kg8 (31...Kf7 32.Ng5+ Kg8 33.Qb3 {White wins}) 32.Rh8+ Kf7 (32...Kxh8 33.Qh6+ Kg8 34.Qg7#) 33.Ng5+ Kg7 34.Rxa8 {White wins}

Correct solutions:
Owen - 25 points
Alex, Andy Y, Humphrey, Nathaniel - 24 points
Andy Q, Karl, Edwin, James - 16 points

Owen - 209 points
Karl - 200 points
Andy Q - 199 points
Andy Y - 198 points
Humphrey - 160 points
Alex - 158 points
Edwin - 152 points
James - 118 points
Jeffrey - 118 points
Amir - 103 points
Nathaniel - 85 points
Rick, Marko - 10 points


Crucial defensive moment